History log of /linux-master/drivers/usb/core/urb.c
Revision Date Author Comments
# 1e4c5742 08-Aug-2023 Alan Stern <stern@rowland.harvard.edu>

USB: Remove remnants of Wireless USB and UWB

Wireless USB has long been defunct, and kernel support for it was
removed in 2020 by commit caa6772db4c1 ("Staging: remove wusbcore and
UWB from the kernel tree.").

Nevertheless, some vestiges of the old implementation still clutter up
the USB subsystem and one or two other places. Let's get rid of them
once and for all.

The only parts still left are the user-facing APIs in
include/uapi/linux/usb/ch9.h. (There are also a couple of misleading
instances, such as the Sierra Wireless USB modem, which is a USB modem
made by Sierra Wireless.)

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/b4f2710f-a2de-4fb0-b50f-76776f3a961b@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 553a8018 15-Sep-2022 Alexander Potapenko <glider@google.com>

kmsan: handle memory sent to/from USB

Depending on the value of is_out kmsan_handle_urb() KMSAN either marks the
data copied to the kernel from a USB device as initialized, or checks the
data sent to the device for being initialized.

Link: https://lkml.kernel.org/r/20220915150417.722975-24-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>


# 26fbe977 24-Jan-2022 Alan Stern <stern@rowland.harvard.edu>

USB: core: Fix hang in usb_kill_urb by adding memory barriers

The syzbot fuzzer has identified a bug in which processes hang waiting
for usb_kill_urb() to return. It turns out the issue is not unlinking
the URB; that works just fine. Rather, the problem arises when the
wakeup notification that the URB has completed is not received.

The reason is memory-access ordering on SMP systems. In outline form,
usb_kill_urb() and __usb_hcd_giveback_urb() operating concurrently on
different CPUs perform the following actions:

CPU 0 CPU 1
---------------------------- ---------------------------------
usb_kill_urb(): __usb_hcd_giveback_urb():
... ...
atomic_inc(&urb->reject); atomic_dec(&urb->use_count);
... ...
wait_event(usb_kill_urb_queue,
atomic_read(&urb->use_count) == 0);
if (atomic_read(&urb->reject))
wake_up(&usb_kill_urb_queue);

Confining your attention to urb->reject and urb->use_count, you can
see that the overall pattern of accesses on CPU 0 is:

write urb->reject, then read urb->use_count;

whereas the overall pattern of accesses on CPU 1 is:

write urb->use_count, then read urb->reject.

This pattern is referred to in memory-model circles as SB (for "Store
Buffering"), and it is well known that without suitable enforcement of
the desired order of accesses -- in the form of memory barriers -- it
is entirely possible for one or both CPUs to execute their reads ahead
of their writes. The end result will be that sometimes CPU 0 sees the
old un-decremented value of urb->use_count while CPU 1 sees the old
un-incremented value of urb->reject. Consequently CPU 0 ends up on
the wait queue and never gets woken up, leading to the observed hang
in usb_kill_urb().

The same pattern of accesses occurs in usb_poison_urb() and the
failure pathway of usb_hcd_submit_urb().

The problem is fixed by adding suitable memory barriers. To provide
proper memory-access ordering in the SB pattern, a full barrier is
required on both CPUs. The atomic_inc() and atomic_dec() accesses
themselves don't provide any memory ordering, but since they are
present, we can use the optimized smp_mb__after_atomic() memory
barrier in the various routines to obtain the desired effect.

This patch adds the necessary memory barriers.

CC: <stable@vger.kernel.org>
Reported-and-tested-by: syzbot+76629376e06e2c2ad626@syzkaller.appspotmail.com
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/Ye8K0QYee0Q0Nna2@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 7652dd2c 26-May-2021 Alan Stern <stern@rowland.harvard.edu>

USB: core: Check buffer length matches wLength for control transfers

A type of inconsistency that can show up in control URBs is when the
setup packet's wLength value does not match the URB's
transfer_buffer_length field. The two should always be equal;
differences could lead to information leaks or undefined behavior for
OUT transfers or overruns for IN transfers.

This patch adds a test for such mismatches during URB submission. If
the test fails, the submission is rejected with a -EBADR error code
(which is not used elsewhere in the USB core), and a debugging message
is logged for people interested in tracking down these errors.

Reviewed-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20210526153244.GA1400430@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 5cc59c41 21-May-2021 Alan Stern <stern@rowland.harvard.edu>

USB: core: WARN if pipe direction != setup packet direction

When a control URB is submitted, the direction indicated by URB's pipe
member is supposed to match the direction indicated by the setup
packet's bRequestType member. A mismatch could lead to trouble,
depending on which field the host controller drivers use for
determining the actual direction.

This shouldn't ever happen; it would represent a careless bug in a
kernel driver somewhere. This patch adds a dev_WARN_ONCE to let
people know about the potential problem.

Suggested-by: "Geoffrey D. Bennett" <g@b4.vu>
Reviewed-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20210522021623.GB1260282@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# fcc2cc1f 14-Sep-2020 Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: move snd_usb_pipe_sanity_check into the USB core

snd_usb_pipe_sanity_check() is a great function, so let's move it into
the USB core so that other parts of the kernel, including the USB core,
can call it.

Name it usb_pipe_type_check() to match the existing
usb_urb_ep_type_check() call, which now uses this function.

Cc: Jaroslav Kysela <perex@perex.cz>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Eli Billauer <eli.billauer@gmail.com>
Cc: Emiliano Ingrassia <ingrassia@epigenesys.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Alexander Tsoy <alexander@tsoy.me>
Cc: "Geoffrey D. Bennett" <g@b4.vu>
Cc: Jussi Laako <jussi@sonarnerd.net>
Cc: Nick Kossifidis <mickflemm@gmail.com>
Cc: Dmitry Panchenko <dmitry@d-systems.ee>
Cc: Chris Wulff <crwulff@gmail.com>
Cc: Jesus Ramos <jesus-ramos@live.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20200914153756.3412156-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# fbc29943 30-Jul-2020 Eli Billauer <eli.billauer@gmail.com>

usb: core: Solve race condition in anchor cleanup functions

usb_kill_anchored_urbs() is commonly used to cancel all URBs on an
anchor just before releasing resources which the URBs rely on. By doing
so, users of this function rely on that no completer callbacks will take
place from any URB on the anchor after it returns.

However if this function is called in parallel with __usb_hcd_giveback_urb
processing a URB on the anchor, the latter may call the completer
callback after usb_kill_anchored_urbs() returns. This can lead to a
kernel panic due to use after release of memory in interrupt context.

The race condition is that __usb_hcd_giveback_urb() first unanchors the URB
and then makes the completer callback. Such URB is hence invisible to
usb_kill_anchored_urbs(), allowing it to return before the completer has
been called, since the anchor's urb_list is empty.

Even worse, if the racing completer callback resubmits the URB, it may
remain in the system long after usb_kill_anchored_urbs() returns.

Hence list_empty(&anchor->urb_list), which is used in the existing
while-loop, doesn't reliably ensure that all URBs of the anchor are gone.

A similar problem exists with usb_poison_anchored_urbs() and
usb_scuttle_anchored_urbs().

This patch adds an external do-while loop, which ensures that all URBs
are indeed handled before these three functions return. This change has
no effect at all unless the race condition occurs, in which case the
loop will busy-wait until the racing completer callback has finished.
This is a rare condition, so the CPU waste of this spinning is
negligible.

The additional do-while loop relies on usb_anchor_check_wakeup(), which
returns true iff the anchor list is empty, and there is no
__usb_hcd_giveback_urb() in the system that is in the middle of the
unanchor-before-complete phase. The @suspend_wakeups member of
struct usb_anchor is used for this purpose, which was introduced to solve
another problem which the same race condition causes, in commit
6ec4147e7bdb ("usb-anchor: Delay usb_wait_anchor_empty_timeout wake up
till completion is done").

The surely_empty variable is necessary, because usb_anchor_check_wakeup()
must be called with the lock held to prevent races. However the spinlock
must be released and reacquired if the outer loop spins with an empty
URB list while waiting for the unanchor-before-complete passage to finish:
The completer callback may very well attempt to take the very same lock.

To summarize, using usb_anchor_check_wakeup() means that the patched
functions can return only when the anchor's list is empty, and there is
no invisible URB being processed. Since the inner while loop finishes on
the empty list condition, the new do-while loop will terminate as well,
except for when the said race condition occurs.

Signed-off-by: Eli Billauer <eli.billauer@gmail.com>
Acked-by: Oliver Neukum <oneukum@suse.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20200731054650.30644-1-eli.billauer@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 0d9b6d49 07-Jul-2020 Gustavo A. R. Silva <gustavoars@kernel.org>

usb: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20200707195607.GA4198@embeddedor
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 1cd17f7f 27-Nov-2019 Emiliano Ingrassia <ingrassia@epigenesys.com>

usb: core: urb: fix URB structure initialization function

Explicitly initialize URB structure urb_list field in usb_init_urb().
This field can be potentially accessed uninitialized and its
initialization is coherent with the usage of list_del_init() in
usb_hcd_unlink_urb_from_ep() and usb_giveback_urb_bh() and its
explicit initialization in usb_hcd_submit_urb() error path.

Signed-off-by: Emiliano Ingrassia <ingrassia@epigenesys.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20191127160355.GA27196@ingrassia.epigenesys.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 6756f4c3 08-Jan-2019 Gustavo A. R. Silva <gustavo@embeddedor.com>

USB: core: urb: Use struct_size() in kmalloc()

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
int stuff;
void *entry[];
};

instance = kmalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kmalloc(struct_size(instance, entry, count), GFP_KERNEL);

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# edb92eaf 16-Mar-2018 Thinh Nguyen <Thinh.Nguyen@synopsys.com>

usb: core: urb: Check SSP isoc ep comp descriptor

The maximum bytes per interval for USB SuperSpeed Plus can be set by
isoc endpoint companion descriptor when it is above 48K. If the
descriptor is provided, then use its value.

USB 3.1 spec 9.6.8

Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# aa15d3d2 11-Dec-2017 Alan Stern <stern@rowland.harvard.edu>

USB: remove the URB_NO_FSBR flag

The URB_NO_FSBR flag has never really been used. It was introduced as
a potential way for UHCI to minimize PCI bus usage (by not attempting
full-speed bulk and control transfers more than once per frame), but
the flag was not set by any drivers.

There's no point in keeping it around. This patch simplifies the API
by removing it. Unfortunately, it does have to be kept as part of the
usbfs ABI, but at least we can document in
include/uapi/linux/usbdevice_fs.h that it doesn't do anything.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# aa1f3bb5 03-Nov-2017 Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: core: move existing SPDX tags to top of the file

To match the rest of the kernel, the SPDX tags for the drivers/usb/core/
files are moved to the first line of the file. This makes it more
obvious the tag is present as well as making it match the other 12k
files in the tree with this location.

It also uses // to match the "expected style" as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 4f4ee7d8 23-Oct-2017 Gustavo A. R. Silva <garsilva@embeddedor.com>

usb: core: urb: mark expected switch fall-through

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Addresses-Coverity-ID: 1162594
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# e901b9873 04-Oct-2017 Takashi Iwai <tiwai@suse.de>

usb: core: Add a helper function to check the validity of EP type in URB

This patch adds a new helper function to perform a sanity check of the
given URB to see whether it contains a valid endpoint. It's a light-
weight version of what usb_submit_urb() does, but without the kernel
warning followed by the stack trace, just returns an error code.

Especially for a driver that doesn't parse the descriptor but fills
the URB with the fixed endpoint (e.g. some quirks for non-compliant
devices), this kind of check is preferable at the probe phase before
actually submitting the urb.

Tested-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>


# 2f964780 16-May-2017 Vamsi Krishna Samavedam <vskrishn@codeaurora.org>

USB: core: replace %p with %pK

Format specifier %p can leak kernel addresses while not valuing the
kptr_restrict system settings. When kptr_restrict is set to (1), kernel
pointers printed using the %pK format specifier will be replaced with
Zeros. Debugging Note : &pK prints only Zeros as address. If you need
actual address information, write 0 to kptr_restrict.

echo 0 > /proc/sys/kernel/kptr_restrict

[Found by poking around in a random vendor kernel tree, it would be nice
if someone would actually send these types of patches upstream - gkh]

Signed-off-by: Vamsi Krishna Samavedam <vskrishn@codeaurora.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 5909cbc8 13-Nov-2016 Mike Krinkin <krinkin.m.u@gmail.com>

usb: core: urb make use of usb_endpoint_maxp_mult

Since usb_endpoint_maxp now returns only lower 11 bits mult
calculation here isn't correct anymore and that breaks webcam
for me. Patch make use of usb_endpoint_maxp_mult instead of
direct calculation.

Fixes: abb621844f6a ("usb: ch9: make usb_endpoint_maxp() return
only packet size")

Signed-off-by: Mike Krinkin <krinkin.m.u@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>


# b65fba3d 28-Oct-2016 Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: core: add missing license information to some files

Some of the USB core files were missing explicit license information.
As all files in the kernel tree are implicitly licensed under the
GPLv2-only, be explicit in case someone get confused looking at
individual files by using the SPDX nomenclature.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# b62a7a99 25-Aug-2016 Wolfram Sang <wsa-dev@sang-engineering.com>

usb: core: urb: don't print on ENOMEM

All kmalloc-based functions print enough information on failures.

Signed-off-by: Wolfram Sang <wsa-dev@sang-engineering.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 8a1b2725 10-Dec-2015 Mathias Nyman <mathias.nyman@linux.intel.com>

usb: define USB_SPEED_SUPER_PLUS speed for SuperSpeedPlus USB3.1 devices

Add a new USB_SPEED_SUPER_PLUS device speed, and make sure usb core can
handle the new speed.
In most cases the behaviour is the same as with USB_SPEED_SUPER SuperSpeed
devices. In a few places we add a "Plus" string to inform the user of the
new speed.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# ae416ba4 25-Oct-2015 Jonas Hesselmann <jonas.hesselmann@hotmail.de>

USB: core: Codestyle fix in urb.c

Delete braces around single statement block suggested by checkpatch.pl

Signed-off-by: Jonas Hesselmann <jonas.hesselmann@hotmail.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 9672f0fe 20-Jul-2014 Amit Virdi <amit.virdi@st.com>

usb: core: allow zero packet flag for interrupt urbs

Section 4.4.7.2 "Interrupt Transfer Bandwidth Requirements" of the USB3.0 spec
says:
A zero-length data payload is a valid transfer and may be useful for
some implementations.

So, extend the logic of allowing URB_ZERO_PACKET to interrupt urbs too.
Otherwise, the kernel throws warning of BOGUS transfer flags.

Signed-off-by: Amit Virdi <amit.virdi@st.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# e227867f 18-Feb-2014 Masanari Iida <standby24x7@gmail.com>

treewide: Fix typo in Documentation/DocBook

This patch fix spelling typo in Documentation/DocBook.
It is because .html and .xml files are generated by make htmldocs,
I have to fix a typo within the source files.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>


# 803a5362 08-Jan-2014 Paul Gortmaker <paul.gortmaker@windriver.com>

usb: delete non-required instances of include <linux/init.h>

None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>. Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 025d4430 03-Jan-2014 Rahul Bedarkar <rahulbedarkar89@gmail.com>

USB: core: correct spelling mistakes in comments and warning

Signed-off-by: Rahul Bedarkar <rahulbedarkar89@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 3482528e 19-Dec-2013 Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: core: remove CONFIG_USB_DEBUG usage

CONFIG_USB_DEBUG is going away, so remove the few places in the USB core
that relied on them.

This means that we always now do the "debug" checks for every urb
submitted, which is a good idea, as who knows how many driver bugs we
have been ignoring when people forget to enable this option. Also, with
the overall speed of USB, doing these extra checks should not cause any
additional overhead.

Also, no longer announce all devices being added to the system if
CONFIG_USB_DEBUG is enabled, as it's not going to be around much longer.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# a2cd612d 09-Dec-2013 Thomas Pugliese <thomas.pugliese@gmail.com>

usb: core: allow isoc URBs for wireless devices with an interval < 6

In usb_submit_urb, do not fail if an isoc URB for a wireless USB device
has an interval < 6. Per WUSB spec, isoc endpoints can support values
from 1-16. Valid values for interrupt URBs for wireless USB devices are
still 6-16.

Signed-off-by: Thomas Pugliese <thomas.pugliese@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 6ec4147e 09-Oct-2013 Hans de Goede <hdegoede@redhat.com>

usb-anchor: Delay usb_wait_anchor_empty_timeout wake up till completion is done

usb_wait_anchor_empty_timeout() should wait till the completion handler
has run. Both the zd1211rw driver and the uas driver (in its task mgmt) depend
on the completion handler having completed when usb_wait_anchor_empty_timeout()
returns, as they read state set by the completion handler after an
usb_wait_anchor_empty_timeout() call.

But __usb_hcd_giveback_urb() calls usb_unanchor_urb before calling the
completion handler. This is necessary as the completion handler may
re-submit and re-anchor the urb. But this introduces a race where the state
these drivers want to read has not been set yet by the completion handler
(this race is easily triggered with the uas task mgmt code).

I've considered adding an anchor_count to struct urb, which would be
incremented on anchor and decremented on unanchor, and then only actually
do the anchor / unanchor on 0 -> 1 and 1 -> 0 transtions, combined with
moving the unanchor call in hcd_giveback_urb to after calling the completion
handler. But this will only work if urb's are only re-anchored to the same
anchor as they were anchored to before the completion handler ran.

And at least one driver re-anchors to another anchor from the completion
handler (rtlwifi).

So I have come up with this patch instead, which adds the ability to
suspend wakeups of usb_wait_anchor_empty_timeout() waiters to the usb_anchor
functionality, and uses this in __usb_hcd_giveback_urb() to delay wake-ups
until the completion handler has run.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# bcc48f1a 08-Aug-2013 Ming Lei <ming.lei@canonical.com>

USB: introduce usb_device_no_sg_constraint() helper

Some host controllers(such as xHCI) can support building
packet from discontinuous buffers, so introduce one flag
and helper for this kind of host controllers, then the
feature can help some applications(such as usbnet) by
supporting arbitrary length of sg buffers.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 626f090c 02-Aug-2013 Yacine Belkadi <yacine.belkadi.1@gmail.com>

usb: fix some scripts/kernel-doc warnings

When building the htmldocs (in verbose mode), scripts/kernel-doc reports the
following type of warnings:

Warning(drivers/usb/core/usb.c:76): No description found for return value of
'usb_find_alt_setting'

Fix them by:
- adding some missing descriptions of return values
- using "Return" sections for those descriptions

Signed-off-by: Yacine Belkadi <yacine.belkadi.1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 10e232c5 27-Jun-2013 Ming Lei <ming.lei@canonical.com>

USB: check sg buffer size in usb_submit_urb

USB spec stats that short packet can only appear at the end
of transfer. Because lost of HC(EHCI/UHCI/OHCI/...) can't
build a full packet from discontinuous buffers, we introduce
the limit in usb_submit_urb() to avoid such kind of bad sg buffers
coming from driver.

The limit might be a bit strict:
- platform has iommu to do sg list mapping
- some host controllers may support to build full packet from
discontinuous buffers.

But considered that most of HCs don't support that, and driver
need work well or keep consistent on different HCs and ARCHs, we
have to introduce the limit.

Currently, only usbtest is reported to pass such sg buffers to HC,
and other users(mass storage, usbfs) don't have the problem.

We don't check it on USB wireless device, because:
- wireless devices can't be attached to common USB
bus(EHCI/UHCI/OHCI/...)
- the max packet size of endpoint may be odd, and often can't
devide 4KB which is a typical usage in usb mass storage application

Reported-by: Konstantin Filatov <kfilatov@parallels.com>
Reported-by: Denis V. Lunev <den@openvz.org>
Cc: Felipe Balbi <balbi@ti.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 68a2bed1 20-Mar-2013 Johan Hovold <johan@kernel.org>

USB: fix urb-poison imbalance

The calls to usb_poison_urb and usb_unpoison_urb are expected to be
balanced. However, if an urb that has not yet been submitted is
poisoned, its reject counter will not be increased as its ep-field is
NULL. A consecutive call to unpoison will thus in fact poison the urb
as its reject counter will be decremented to a negative value,
effectively preventing the urb from being submitted.

Note that there are currently no in-kernel drivers affected by this.

Cc: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 2f02bc8a 07-Nov-2012 Alan Stern <stern@rowland.harvard.edu>

USB: report submission of active URBs

This patch (as1633) changes slightly the way usbcore handled
submissions of URBs that are already active. It will now return
-EBUSY rather than -EINVAL, and it will call WARN_ONCE to draw
people's attention to the bug.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# a03bede5 01-Oct-2012 Alan Stern <stern@rowland.harvard.edu>

USB: update documentation for URB_ISO_ASAP

This patch (as1611) updates the USB documentation and kerneldoc to
give a more precise meaning for the URB_ISO_ASAP flag and to explain
more of the details of scheduling for isochronous URBs.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 8815bb09 30-Apr-2012 Oliver Neukum <oliver@neukum.org>

usbhid: prevent deadlock during timeout

On some HCDs usb_unlink_urb() can directly call the
completion handler. That limits the spinlocks that can
be taken in the handler to locks not held while calling
usb_unlink_urb()
To prevent a race with resubmission, this patch exposes
usbcore's infrastructure for blocking submission, uses it
and so drops the lock without causing a race in usbhid.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# da8bfb09 28-Mar-2012 Alan Stern <stern@rowland.harvard.edu>

USB documentation: explain lifetime rules for unlinking URBs

This patch (as1534c) updates the documentation for usb_unlink_urb and
related functions. It explains that the caller must prevent the URB
being unlinked from getting deallocated while the unlink is taking
place.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 371f3b49 29-Feb-2012 Sebastian Andrzej Siewior <bigeasy@linutronix.de>

usb/core: remove "always" from usb_unlink_urb() kernel doc entry

The kernel doc entry for usb_unlink_urb() contains the phrase "This
request is always asynchronous.". The "always" leads to the assumption
that the ->complete() callback is not called from within
usb_unlink_urb(). This is not true. The HCD is allowed to call the
->complete() from within ->urb_dequeue() if it is appropriate for the
hardware.
This patch updates the kernel doc so usb-device driver authors make sure
to drop all locks (and make sure it is okay to drop them) which are
acquired by the complete callback before calling usb_unlink_urb().

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 0cb54a3e 02-Feb-2012 Alan Stern <stern@rowland.harvard.edu>

USB: debugging code shouldn't alter control flow

People have complained that debugging code shouldn't alter the flow of
control; it should restrict itself to printing out warnings and error
messages. Bowing to popular opinion, this patch (as1518) changes the
debugging checks in usb_submit_urb() to follow this guideline.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Keith Packard <keithp@keithp.com>
CC: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


# 29cc8897 23-Aug-2011 Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>

USB: use usb_endpoint_maxp() instead of le16_to_cpu()

Now ${LINUX}/drivers/usb/* can use usb_endpoint_maxp(desc) to get maximum packet size
instead of le16_to_cpu(desc->wMaxPacketSize).
This patch fix it up

Cc: Armin Fuerst <fuerst@in.tum.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Johannes Erdfelt <johannes@erdfelt.com>
Cc: Vojtech Pavlik <vojtech@suse.cz>
Cc: Oliver Neukum <oliver@neukum.name>
Cc: David Kubicek <dave@awk.cz>
Cc: Johan Hovold <jhovold@gmail.com>
Cc: Brad Hards <bhards@bigpond.net.au>
Acked-by: Felipe Balbi <balbi@ti.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Dahlmann <dahlmann.thomas@arcor.de>
Cc: David Brownell <david-b@pacbell.net>
Cc: David Lopo <dlopo@chipidea.mips.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Michal Nazarewicz <m.nazarewicz@samsung.com>
Cc: Xie Xiaobo <X.Xie@freescale.com>
Cc: Li Yang <leoli@freescale.com>
Cc: Jiang Bo <tanya.jiang@freescale.com>
Cc: Yuan-hsin Chen <yhchen@faraday-tech.com>
Cc: Darius Augulis <augulis.darius@gmail.com>
Cc: Xiaochen Shen <xiaochen.shen@intel.com>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: OKI SEMICONDUCTOR, <toshiharu-linux@dsn.okisemi.com>
Cc: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: Ben Dooks <ben@simtec.co.uk>
Cc: Thomas Abraham <thomas.ab@samsung.com>
Cc: Herbert Pötzl <herbert@13thfloor.at>
Cc: Arnaud Patard <arnaud.patard@rtp-net.org>
Cc: Roman Weissgaerber <weissg@vienna.at>
Acked-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Tony Olech <tony.olech@elandigitalsystems.com>
Cc: Florian Floe Echtler <echtler@fs.tum.de>
Cc: Christian Lucht <lucht@codemercs.com>
Cc: Juergen Stuber <starblue@sourceforge.net>
Cc: Georges Toth <g.toth@e-biz.lu>
Cc: Bill Ryder <bryder@sgi.com>
Cc: Kuba Ober <kuba@mareimbrium.org>
Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 500132a0 28-Feb-2011 Paul Zimmerman <Paul.Zimmerman@synopsys.com>

USB: Add support for SuperSpeed isoc endpoints

Use the Mult and bMaxBurst values from the endpoint companion
descriptor to calculate the max length of an isoc transfer.

Add USB_SS_MULT macro to access Mult field of bmAttributes, at
Sarah's suggestion.

This patch should be queued for the 2.6.36 and 2.6.37 stable trees, since
those were the first kernels to have isochronous support for SuperSpeed
devices.

Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@kernel.org


# f7dd6491 30-Aug-2010 Simon Arlott <simon@octiron.net>

USB: output an error message when the pipe type doesn't match the endpoint type

Commit f661c6f8c67bd55e93348f160d590ff9edf08904 adds a check of the pipe type if
CONFIG_USB_DEBUG is enabled, but it doesn't output anything if this scenario
occurs.

Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# b3e67044 02-Aug-2010 Christian Lamparter <chunkeey@googlemail.com>

USB: fix thread-unsafe anchor utiliy routines

This patch fixes a race condition in two utility routines
related to the removal/unlinking of urbs from an anchor.

If two threads are concurrently accessing the same anchor,
both could end up with the same urb - thinking they are
the exclusive owner.

Alan Stern pointed out a related issue in
usb_unlink_anchored_urbs:

"The URB isn't removed from the anchor until it completes
(as a by-product of completion, in fact), which might not
be for quite some time after the unlink call returns.
In the meantime, the subroutine will keep trying to unlink
it, over and over again."

Cc: stable <stable@kernel.org>
Cc: Oliver Neukum <oneukum@suse.de>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# fe54b058 30-Apr-2010 Matthew Wilcox <willy@infradead.org>

USB: Add a usb_pipe_endpoint() convenience function

Converting a pipe number to a struct usb_host_endpoint pointer is a little
messy. Introduce a new convenience function to hide the mess.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# ff9c895f 02-Apr-2010 Alan Stern <stern@rowland.harvard.edu>

USB: fix usbmon and DMA mapping for scatter-gather URBs

This patch (as1368) fixes a rather obscure bug in usbmon: When tracing
URBs sent by the scatter-gather library, it accesses the data buffers
while they are still mapped for DMA.

The solution is to move the mapping and unmapping out of the s-g
library and into the usual place in hcd.c. This requires the addition
of new URB flag bits to describe the kind of mapping needed, since we
have to call dma_map_sg() if the HCD supports native scatter-gather
operation and dma_map_page() if it doesn't. The nice thing about
having the new flags is that they simplify the testing for unmapping.

The patch removes the only caller of usb_buffer_[un]map_sg(), so those
functions are #if'ed out. A later patch will remove them entirely.

As a result of this change, urb->sg will be set in situations where
it wasn't set previously. Hence the xhci and whci drivers are
adjusted to test urb->num_sgs instead, which retains its original
meaning and is nonzero only when the HCD has to handle a scatterlist.

Finally, even when a submission error occurs we don't want to hand
URBs to usbmon before they are unmapped. The submission path is
rearranged so that map_urb_for_dma() is called only for non-root-hub
URBs and unmap_urb_for_dma() is called immediately after a submission
error. This simplifies the error handling.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 0ede76fc 05-Mar-2010 Alan Stern <stern@rowland.harvard.edu>

USB: remove uses of URB_NO_SETUP_DMA_MAP

This patch (as1350) removes all usages of coherent buffers for USB
control-request setup-packet buffers. There's no good reason to
reserve coherent memory for these things; control requests are hardly
ever used in large quantity (the major exception is firmware
transfers, and they aren't time-critical). Furthermore, only seven
drivers used it. We might as well always use streaming DMA mappings
for setup-packet buffers, and remove some extra complexity from
usbcore.

The DMA-mapping portion of hcd.c is currently in flux. A separate
patch will be submitted to remove support for URB_NO_SETUP_DMA_MAP
after everything else settles down. The removal should go smoothly,
as by then nobody will be using it.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 27729aad 24-Apr-2010 Eric Lescouet <Eric.Lescouet@virtuallogix.com>

USB: make hcd.h public (drivers dependency)

The usbcore headers: hcd.h and hub.h are shared between usbcore,
HCDs and a couple of other drivers (e.g. USBIP modules).
So, it makes sense to move them into a more public location and
to cleanup dependency of those modules on kernel internal headers.
This patch moves hcd.h from drivers/usb/core into include/linux/usb/

Signed-of-by: Eric Lescouet <eric@lescouet.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# f09a15e6 16-Mar-2010 Matthew Wilcox <willy@infradead.org>

USB: Fix usb_fill_int_urb for SuperSpeed devices

USB 3 and Wireless USB specify a logarithmic encoding of the endpoint
interval that matches the USB 2 specification. usb_fill_int_urb() didn't
know that and was filling in the interval as if it was USB 1.1. Fix
usb_fill_int_urb() for SuperSpeed devices, but leave the wireless case
alone, because David Vrabel wants to keep the old encoding.

Update the struct urb kernel doc to note that SuperSpeed URBs must have
urb->interval specified in microframes.

Add a missing break statement in the usb_submit_urb() interrupt URB
checking, since wireless USB and SuperSpeed USB encode urb->interval
differently. This allows xHCI roothubs to actually register with khubd.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 551cdbbe 14-Jan-2010 Greg Kroah-Hartman <gregkh@suse.de>

USB: rename USB_SPEED_VARIABLE to USB_SPEED_WIRELESS

It's really the wireless speed, so rename the thing to make
more sense. Based on a recommendation from David Vrabel

Cc: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# f661c6f8 11-Dec-2009 Alan Stern <stern@rowland.harvard.edu>

USB: check the endpoint type against the pipe type

This patch (as1316) adds some error checking to usb_submit_urb().
It's conditional on CONFIG_USB_DEBUG, so it won't affect normal users.
The new check makes sure that the actual type of the endpoint
described by urb->pipe agrees with the type encoded in the pipe value.

The USB error code documentation is updated to include the code
returned by the new check, and the usbfs SUBMITURB handler is updated
to use the correct pipe type when legacy user code tries to submit a
bulk transfer to an interrupt endpoint.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 8e08b976 18-Aug-2009 David Vrabel <david.vrabel@csr.com>

USB: allow interrupt transfers to WUSB devices

Check urb->interval on interrupt transfers and allow those with valid
values (6 <= interval <= 16).

Signed-off-by: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 79abb1ab 27-Apr-2009 Sarah Sharp <sarah.a.sharp@linux.intel.com>

USB: Support for bandwidth allocation.

Originally, the USB core had no support for allocating bandwidth when a
particular configuration or alternate setting for an interface was
selected. Instead, the device driver's URB submission would fail if
there was not enough bandwidth for a periodic endpoint. Drivers could
work around this, by using the scatter-gather list API to guarantee
bandwidth.

This patch adds host controller API to allow the USB core to allocate or
deallocate bandwidth for an endpoint. Endpoints are added to or dropped
from a copy of the current schedule by calling add_endpoint() or
drop_endpoint(), and then the schedule is atomically evaluated with a
call to check_bandwidth(). This allows all the endpoints for a new
configuration or alternate setting to be added at the same time that the
endpoints from the old configuration or alt setting are dropped.

Endpoints must be added to the schedule before any URBs are submitted to
them. The HCD must be allowed to reject a new configuration or alt
setting before the control transfer is sent to the device requesting the
change. It may reject the change because there is not enough bandwidth,
not enough internal resources (such as memory on an embedded host
controller), or perhaps even for security reasons in a virtualized
environment.

If the call to check_bandwidth() fails, the USB core must call
reset_bandwidth(). This causes the schedule to be reverted back to the
state it was in just after the last successful check_bandwidth() call.

If the call succeeds, the host controller driver (and hardware) will have
changed its internal state to match the new configuration or alternate
setting. The USB core can then issue a control transfer to the device to
change the configuration or alt setting. This allows the core to test new
configurations or alternate settings before unbinding drivers bound to
interfaces in the old configuration.

WIP:

The USB core must add endpoints from all interfaces in a configuration
to the schedule, because a driver may claim that interface at any time.
A slight optimization might be to add the endpoints to the schedule once
a driver claims that interface. FIXME

This patch does not cover changing alternate settings, but it does
handle a configuration change or de-configuration. FIXME

The code for managing the schedule is currently HCD specific. A generic
scheduling algorithm could be added for host controllers without
built-in scheduling support. For now, if a host controller does not
define the check_bandwidth() function, the call to
usb_hcd_check_bandwidth() will always succeed.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 6b403b02 27-Apr-2009 Sarah Sharp <sarah.a.sharp@linux.intel.com>

USB: Add SuperSpeed to the list of USB device speeds.

Modify the USB core to handle the new USB 3.0 speed, "SuperSpeed". This
is 5.0 Gbps (wire speed). There are probably more places that check for
speed that I've missed.

SuperSpeed devices have a 512 byte endpoint 0 max packet size. This shows
up as a bMaxPacketSize0 set to 0x09 (see table 9-8 of the USB 3.0 bus
spec).

xHCI spec says that the xHC can handle intervals up to 2^15 microframes. That
might change when real silicon becomes available.

Add FIXME note for SuperSpeed isochronous endpoints. They can transmit up
to 16 packets in one "burst" before they wait for an acknowledgment of the
packets. They can do up to 3 bursts per microframe (determined by the
mult value in the endpoint companion descriptor). The xHCI driver doesn't
have support for isoc yet, so fix this later.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 71d2718f 12-Mar-2009 Roel Kluin <roel.kluin@gmail.com>

USB: more u32 conversion after transfer_buffer_length and actual_length

transfer_buffer_length and actual_length have become unsigned, therefore some
additional conversion of local variables, function arguments and print
specifications is desired.

A test for a negative urb->transfer_buffer_length became obsolete; instead
we ensure that it does not exceed INT_MAX. Also, urb->actual_length is always
less than urb->transfer_buffer_length.

rh_string() does no longer return -EPIPE in the case of an unsupported ID.
Instead its only caller, rh_call_control() does the check.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 6da9c990 18-Feb-2009 David Vrabel <david.vrabel@csr.com>

USB: allow libusb to talk to unauthenticated WUSB devices

To permit a userspace application to associate with WUSB devices
using numeric association, control transfers to unauthenticated WUSB
devices must be allowed.

This requires that wusbcore correctly sets the device state to
UNAUTHENTICATED, DEFAULT and ADDRESS and that control transfers can be
performed to UNAUTHENTICATED devices.

Signed-off-by: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 856395d6 18-Dec-2008 Oliver Neukum <oliver@neukum.org>

USB: extension of anchor API to unpoison an anchor

This extension allows unpoisoning an anchor allowing drivers that
resubmit URBs to reuse an anchor for methods like resume()

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 49367d8f 12-Dec-2008 Ming Lei <tom.leiming@gmail.com>

USB: mark "reject" field of struct urb as atomic_t

It is enough to protect accesses to reject field of urb
by marking it as atomic_t,also it is the only reason of
existence of usb_reject_lock,so remove the lock to make
code more clean.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 2870fde7 08-Nov-2008 Rabin Vincent <rabin@rab.in>

USB: mention URB_FREE_BUFFER in usb_free_urb documentation

The usb_free_urb comment says that the transfer buffer will not be
freed, but this is not the case when URB_FREE_BUFFER is set.

Signed-off-by: Rabin Vincent <rabin@rab.in>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# cde217a5 21-Oct-2008 Alan Stern <stern@rowland.harvard.edu>

USB: fix crash when URBs are unlinked after the device is gone

This patch (as1151) protects usbcore against drivers that try to
unlink an URB after the URB's device or bus have been removed. The
core does not currently check for this, and certain drivers can cause
a crash if they are running while an HCD is unloaded.

Certainly it would be best to fix the guilty drivers. But a little
defensive programming doesn't hurt, especially since it appears that
quite a few drivers need to be fixed.

The patch prevents the problem by grabbing a reference to the device
while an unlink is in progress and using a new spinlock to synchronize
unlinks with device removal. (There's no need to acquire a reference
to the bus as well, since the device structure itself keeps a
reference to the bus.) In addition, the kerneldoc is updated to
indicate that URBs should not be unlinked after the disconnect method
returns.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 69a85942 14-Aug-2008 Greg Kroah-Hartman <gregkh@suse.de>

USB: remove err() macro from usb core code

USB should not be having it's own printk macros, so remove err() and
use the system-wide standard of dev_err() wherever possible. In the
few places that will not work out, use a basic printk().

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 19876252 25-Aug-2008 Oliver Neukum <oliver@neukum.org>

USB: anchor API changes needed for btusb

This extends the anchor API as btusb needs for autosuspend.


Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 6a2839be 29-Jul-2008 Oliver Neukum <oliver@neukum.org>

USB: extend poisoning to anchors

this extends the poisoning concept to anchors. This way poisoning
will work with fire and forget drivers.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 55b447bf 29-Jul-2008 Oliver Neukum <oliver@neukum.org>

USB: kill URBs permanently

looking at usb_kill_urb() it seems to me that it is unnecessarily lenient.
In the use case of disconnect() you never want to use the URB again
(for the same device) But leaving urb->reject elevated will make it easier
to avoid races between read/write and disconnect.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 77571f05 18-Aug-2008 Oliver Neukum <oliver@neukum.org>

USB: fix bug in usb_unlink_anchored_urbs()

Irqs must not accidentally be reenabled.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 441b62c1 03-Mar-2008 Harvey Harrison <harvey.harrison@gmail.com>

USB: replace remaining __FUNCTION__ occurrences

__FUNCTION__ is gcc-specific, use __func__

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# eda76959 10-Apr-2008 Oliver Neukum <oliver@neukum.org>

USB: add extension of anchor API, usb_unlink_anchored_urbs

This adds the ability to trigger asynchronous unlinks of anchored URBs. This
is needed for error handling in the comntext of completion handlers, which
cannot sleep.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 2c044a48 30-Jan-2008 Greg Kroah-Hartman <gregkh@suse.de>

USB: fix codingstyle issues in drivers/usb/core/*.c

Fixes a number of coding style issues in the remaining .c files in
drivers/usb/core/

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 782e70c6 25-Jan-2008 Greg Kroah-Hartman <gregkh@suse.de>

USB: mark USB drivers as being GPL only

Over two years ago, the Linux USB developers stated that they believed
there was no way to create a USB kernel driver that was not under the
GPL. This patch moves the USB apis to enforce that decision.

There are no known closed source USB drivers in the wild, so this patch
should cause no problems.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 0b28baaf 17-Oct-2007 Oliver Neukum <oliver@neukum.org>

USB: add URB_FREE_BUFFER to permissible flags

URB_FREE_BUFFER needs to be allowed in the sanity checks to use drivers that
use that flag.


Signed-off-by: Oliver Neukum <oneukum@suse.de>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 6840d255 10-Sep-2007 Alan Stern <stern@rowland.harvard.edu>

USB: flush outstanding URBs when suspending

This patch (as989) makes usbcore flush all outstanding URBs for each
device as the device is suspended. This will be true even when
CONFIG_USB_SUSPEND is not enabled.

In addition, an extra can_submit flag is added to the usb_device
structure. That flag will be turned off whenever a suspend request
has been received for the device, even if the device isn't actually
suspended because CONFIG_USB_SUSPEND isn't set.

It's no longer necessary to check for the device state being equal to
USB_STATE_SUSPENDED during URB submission; that check can be replaced
by a check of the can_submit flag. This also permits us to remove
some questionable references to the deprecated power.power_state field.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 1431d2a4 24-Aug-2007 Alan Stern <stern@rowland.harvard.edu>

USB: get rid of urb->lock

Now that urb->status isn't used, urb->lock doesn't protect anything.
This patch (as980) removes it and replaces it with a private mutex in
the one remaining place it was still used: usb_kill_urb.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# d617bc83 02-Aug-2007 Alan Stern <stern@rowland.harvard.edu>

USB: cleanup for previous patches

This patch (as951) cleans up a few loose ends from earlier patches.
Redundant checks for non-NULL urb->dev are removed, as are checks of
urb->dev->bus (which can never be NULL). Conversely, a check for
non-NULL urb->ep is added to the unlink paths.

A homegrown round-down-to-power-of-2 loop is simplified by using the
ilog2 routine. The comparison in usb_urb_dir_in() is made more
transparent.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 4326ed0b 30-Jul-2007 Alan Stern <stern@rowland.harvard.edu>

USB: address-0 handling during device initialization

This patch (as947) changes the device initialization and enumeration
code in hub.c; now udev->devnum will be set to 0 while the device is
being accessed at address 0. Until now this wasn't needed because the
address value was passed as part of urb->pipe; without that field the
device address must be stored elsewhere.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# fea34091 30-Jul-2007 Alan Stern <stern@rowland.harvard.edu>

USB: add direction bit to urb->transfer_flags

This patch (as945) adds a bit to urb->transfer_flags for recording the
direction of the URB. The bit is set/cleared automatically in
usb_submit_urb() so drivers don't have to worry about it (although as
a result, it isn't valid until the URB has been submitted). Inline
routines are added for easily checking an URB's direction. They
replace calls to usb_pipein in the DMA-mapping parts of hcd.c.

For non-control endpoints, the direction is determined directly from
the endpoint descriptor. However control endpoints are
bi-directional; for them the direction is determined from the
bRequestType byte and the wLength value in the setup packet.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 5b653c79 30-Jul-2007 Alan Stern <stern@rowland.harvard.edu>

USB: add urb->ep

This patch (as943) prepares the way for eliminating urb->pipe by
introducing an endpoint pointer into struct urb. For now urb->ep
is set by usb_submit_urb() from the pipe value; eventually drivers
will set it themselves and we will remove urb->pipe completely.

The patch also adds new inline routines to retrieve an endpoint
descriptor's number and transfer type, essentially as replacements for
usb_pipeendpoint and usb_pipetype.

usb_submit_urb(), usb_hcd_submit_urb(), and usb_hcd_unlink_urb() are
converted to use the new field and new routines. Other parts of
usbcore will be converted in later patches.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# beafef07 13-Jul-2007 Alan Stern <stern@rowland.harvard.edu>

USB: documentation update for usb_unlink_urb

This patch (as936) updates the kerneldoc for usb_unlink_urb. The
explanation of how endpoint queues are meant to work is now clearer
and in better agreement with reality.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 8b3b01c8 13-Jun-2007 Marcel Holtmann <marcel@holtmann.org>

USB: Add URB_FREE_BUFFER flag and the logic behind it

USB: Add URB_FREE_BUFFER flag for freeing the transfer buffer

In some cases it is not needed that the driver keeps track of the
transfer buffer of an URB. It can be simply freed along with the
URB itself when the reference count goes down to zero. The new
flag URB_FREE_BUFFER enables this behavior.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 51a2f077 25-May-2007 Oliver Neukum <oneukum@suse.de>

USB: introduce usb_anchor

- introduction of usb_anchor and its methods

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 9251644a 23-Jan-2007 Oliver Neukum <oneukum@suse.de>

usbcore: trivial whitespace fixes

This patch (as844) makes some trivial whitespace fixes to a few files
in usbcore. Oliver did most of the work and Alan added some tidying up.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 896fbd71 16-Jan-2007 Alan Stern <stern@rowland.harvard.edu>

usbcore: remove unused bandwith-related code

This patch (as841) removes from usbcore a couple of support routines
meant to help with bandwidth allocation. With the changes to uhci-hcd
in the previous patch, these routines are no longer used anywhere.
Also removed is the CONFIG_USB_BANDWIDTH option; it no longer does
anything and is no longer needed since the HCDs now handle bandwidth
issues correctly.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# ec17cf1c 13-Sep-2006 Tobias Klauser <tklauser@distanz.ch>

USB: Remove unneeded void * casts in core files

The patch removes unneeded casts for the following (void *) pointers:
- struct file: private
- struct urb: context
- struct usb_bus: hcpriv
- return value of kmalloc()

The patch also contains some whitespace cleanup in the relevant areas.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# a6d2bb9f 30-Aug-2006 Alan Stern <stern@rowland.harvard.edu>

USB: remove struct usb_operations

All of the currently-supported USB host controller drivers use the HCD
bus-glue framework. As part of the program for flattening out the glue
layer, this patch (as769) removes the usb_operations structure. All
function calls now go directly to the HCD routines (slightly renamed
to remain within the "usb_" namespace).

The patch also removes usb_alloc_bus(), because it's not useful in the
HCD framework and it wasn't referenced anywhere.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 6ab3d562 30-Jun-2006 Jörn Engel <joern@wohnheim.fh-wedel.de>

Remove obsolete #include <linux/config.h>

Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>


# e9aa795a 23-Jan-2006 Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] USB: add might_sleep() to usb_unlink_urb() to warn developers

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 654f3118 17-Nov-2005 Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] USB: move CONFIG_USB_DEBUG checks into the Makefile

This lets us remove a lot of code in the drivers that were all checking
the same thing. It also found some bugs in a few of the drivers, which
has been fixed up.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>


# b13296c6 27-Sep-2005 David Brownell <david-b@pacbell.net>

[PATCH] updates for "controller suspended" handling

Reject URBs to _all_ devices when their host controllers are suspended;
even root hub registers will be unavailable. Also, don't reject urbs
to root hubs in other cases; the only upstream link is through that
controller (on PCI or whatever SOC bus is in use).

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/core/hcd.c | 28 ++++++++++++----------------
drivers/usb/core/urb.c | 3 ++-
2 files changed, 14 insertions(+), 17 deletions(-)


# 55016f10 21-Oct-2005 Al Viro <viro@zeniv.linux.org.uk>

[PATCH] gfp_t: drivers/usb

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>


# b375a049 29-Jul-2005 Alan Stern <stern@rowland.harvard.edu>

[PATCH] USB: URB_ASYNC_UNLINK flag removed from the kernel

29 July 2005, Cambridge, MA:

This afternoon Alan Stern submitted a patch to remove the URB_ASYNC_UNLINK
flag from the Linux kernel. Mr. Stern explained, "This flag is a relic
from an earlier, less-well-designed system. For over a year it hasn't
been used for anything other than printing warning messages."

An anonymous spokesman for the Linux kernel development community
commented, "This is exactly the sort of thing we see happening all the
time. As the kernel evolves, support for old techniques and old code can
be jettisoned and replaced by newer, better approaches. Proprietary
operating systems do not have the freedom or flexibility to change so
quickly."

Mr. Stern, a staff member at Harvard University's Rowland Institute who
works on Linux only as a hobby, noted that the patch (labelled as548) did
not update two files, keyspan.c and option.c, in the USB drivers' "serial"
subdirectory. "Those files need more extensive changes," he remarked.
"They examine the status field of several URBs at times when they're not
supposed to. That will need to be fixed before the URB_ASYNC_UNLINK flag
is removed."

Greg Kroah-Hartman, the kernel maintainer responsible for overseeing all
of Linux's USB drivers, did not respond to our inquiries or return our
calls. His only comment was "Applied, thanks."

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 5db539e4 23-Jun-2005 Olav Kongas <ok@artecdesign.ee>

[PATCH] USB: Fix kmalloc's flags type in USB

Greg,

This patch fixes the kmalloc() flags argument type in USB
subsystem; hopefully all of its occurences. The patch was
made against patch-2.6.12-git2 from Jun 20.

Cleanup of flags for kmalloc() in USB subsystem.

Signed-off-by: Olav Kongas <ok@artecdesign.ee>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 093cf723 03-May-2005 Steven Cole <elenstev@mesatop.com>

[PATCH] USB: Spelling fixes for drivers/usb.

Here are some spelling corrections for drivers/usb.

cancelation -> cancellation
succesful -> successful
cancelation -> cancellation
decriptor -> descriptor
Initalize -> Initialize
wierd -> weird
Protocoll -> Protocol
occured -> occurred
successfull -> successful
Procesing -> Processing
devide -> divide
Isochronuous -> Isochronous
noticable -> noticeable
Basicly -> Basically
transfering -> transferring
intialize -> initialize
Incomming -> Incoming
additionnal -> additional
asume -> assume
Unfortunatly -> Unfortunately
retreive -> retrieve
tranceiver -> transceiver
Compatiblity -> Compatibility
Incorprated -> Incorporated
existance -> existence
Ununsual -> Unusual

Signed-off-by: Steven Cole <elenstev@mesatop.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 8835f665 18-Apr-2005 Alan Stern <stern@rowland.harvard.edu>

[PATCH] USB: USB API documentation modification

In response to complaints about excessive latency in the uhci-hcd driver
I'm planning to convert it to a top-half/bottom-half design. It turns out
that to do this, the USB API has to be modified slightly since the driver
will not be able to meet one of the guarantees in the current API. This
patch changes some kerneldoc, specifying the weaker guarantee.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


# 1da177e4 16-Apr-2005 Linus Torvalds <torvalds@ppc970.osdl.org>

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!