leds: triggers: Add helper led_match_default_trigger

Avoid code duplication and factor out common functionality to new
helper led_match_default_trigger().

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/d78eef6f-c18c-4546-b83e-6d1890849154@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>

leds: trigger: Stop exporting trigger_list

Commit 682e98564ffb ("leds: trigger: panic: Simplify
led_trigger_set_panic") removed the last external user of variable
trigger_list. So stop exporting it. If in future a need should arise
again to access this variable, I think we better add some accessor
instead of exporting the variable directly.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/ca185fb1-3a66-46b9-920e-bfecbe39c6bf@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>

leds: trigger: Load trigger modules on-demand if used as default trigger

Even if a trigger is set as default trigger for a LED device,
the respective trigger module (if built as module) isn't automatically
loaded by the kernel if the LED device is registered. I think we can
do better. Try to load the module asynchronously by alias
ledtrig:<trigger name>. This requires that such an alias is added to
relevant triggers.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/79adb260-06ad-443a-a68e-abe4498c3298@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>

leds: trigger: Remove unused function led_trigger_rename_static()

This function was added with a8df7b1ab70b ("leds: add led_trigger_rename
function") 11 yrs ago, but it has no users. So remove it.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/d90f30be-f661-4db7-b0b5-d09d07a78a68@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>

leds: Clear LED_INIT_DEFAULT_TRIGGER when clearing current trigger

Not all triggers use LED_INIT_DEFAULT_TRIGGER, which means that it
will not get cleared when the default trigger is a trigger which
does not use it such as "default-on".

If the default trigger then later gets replaced by a trigger which
does check LED_INIT_DEFAULT_TRIGGER, such as "timer" then that trigger
will behave as if it is the default trigger which it should not do.

To fix this clear the LED_INIT_DEFAULT_TRIGGER flag when clearing
the current trigger, so that it will not be set for any subsequently
set (non default) triggers.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Tested-by: Yauhen Kharuzhy <jekhor@gmail.com>
Link: https://lore.kernel.org/r/20230510162234.291439-5-hdegoede@redhat.com
Signed-off-by: Lee Jones <lee@kernel.org>

leds: Fix oops about sleeping in led_trigger_blink()

led_trigger_blink() calls led_blink_set() from a RCU read-side critical
section so led_blink_set() must not sleep. Note sleeping was not allowed
before the switch to RCU either because a spinlock was held before.

led_blink_set() does not sleep when sw-blinking is used, but
many LED controller drivers with hw blink support have a blink_set
function which may sleep, leading to an oops like this one:

[ 832.605062] ------------[ cut here ]------------
[ 832.605085] Voluntary context switch within RCU read-side critical section!
[ 832.605119] WARNING: CPU: 2 PID: 370 at kernel/rcu/tree_plugin.h:318 rcu_note_context_switch+0x4ee/0x690
<snip>
[ 832.606453] Call Trace:
[ 832.606466] <TASK>
[ 832.606487] __schedule+0x9f/0x1480
[ 832.606527] schedule+0x5d/0xe0
[ 832.606549] schedule_timeout+0x79/0x140
[ 832.606572] ? __pfx_process_timeout+0x10/0x10
[ 832.606599] wait_for_completion_timeout+0x6f/0x140
[ 832.606627] i2c_dw_xfer+0x101/0x460
[ 832.606659] ? psi_group_change+0x168/0x400
[ 832.606680] __i2c_transfer+0x172/0x6d0
[ 832.606709] i2c_smbus_xfer_emulated+0x27d/0x9c0
[ 832.606732] ? __schedule+0x430/0x1480
[ 832.606753] ? preempt_count_add+0x6a/0xa0
[ 832.606778] ? get_nohz_timer_target+0x18/0x190
[ 832.606796] ? lock_timer_base+0x61/0x80
[ 832.606817] ? preempt_count_add+0x6a/0xa0
[ 832.606842] __i2c_smbus_xfer+0xa2/0x3f0
[ 832.606862] i2c_smbus_xfer+0x66/0xf0
[ 832.606882] i2c_smbus_read_byte_data+0x41/0x70
[ 832.606901] ? _raw_spin_unlock_irqrestore+0x23/0x40
[ 832.606922] ? __pm_runtime_suspend+0x46/0xc0
[ 832.606946] cht_wc_byte_reg_read+0x2e/0x60
[ 832.606972] _regmap_read+0x5c/0x120
[ 832.606997] _regmap_update_bits+0x96/0xc0
[ 832.607023] regmap_update_bits_base+0x5b/0x90
[ 832.607053] cht_wc_leds_brightness_get+0x412/0x910 [leds_cht_wcove]
[ 832.607094] led_blink_setup+0x28/0x100
[ 832.607119] led_trigger_blink+0x40/0x70
[ 832.607145] power_supply_update_leds+0x1b7/0x1c0
[ 832.607174] power_supply_changed_work+0x67/0xe0
[ 832.607198] process_one_work+0x1c8/0x3c0
[ 832.607222] worker_thread+0x4d/0x380
[ 832.607243] ? __pfx_worker_thread+0x10/0x10
[ 832.607258] kthread+0xe9/0x110
[ 832.607279] ? __pfx_kthread+0x10/0x10
[ 832.607300] ret_from_fork+0x2c/0x50
[ 832.607337] </TASK>
[ 832.607344] ---[ end trace 0000000000000000 ]---

Add a new led_blink_set_nosleep() function which defers the actual
led_blink_set() call to a workqueue when necessary to fix this.

This also fixes an existing race where a pending led_set_brightness() has
been deferred to set_brightness_work and might then race with a later
led_cdev->blink_set() call. Note this race is only an issue with triggers
mixing led_trigger_event() and led_trigger_blink() calls, sysfs API
calls and led_trigger_blink_oneshot() are not affected.

Note rather then adding a separate blink_set_blocking callback this uses
the presence of the already existing brightness_set_blocking callback to
detect if the blinking call should be deferred to set_brightness_work.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Tested-by: Yauhen Kharuzhy <jekhor@gmail.com>
Link: https://lore.kernel.org/r/20230510162234.291439-4-hdegoede@redhat.com
Signed-off-by: Lee Jones <lee@kernel.org>

leds: Change led_trigger_blink[_oneshot]() delay parameters to pass-by-value

led_blink_set[_oneshot]()'s delay_on and delay_off function parameters
are pass by reference, so that hw-blink implementations can report
back the actual achieved delays when the values have been rounded
to something the hw supports.

This is really only interesting for the sysfs API / the timer trigger.
Other triggers don't really care about this and none of the callers of
led_trigger_blink[_oneshot]() do anything with the returned delay values.

Change the led_trigger_blink[_oneshot]() delay parameters to pass-by-value,
there are 2 reasons for this:

1. led_cdev->blink_set() may sleep, while led_trigger_blink() may not.
So on hw where led_cdev->blink_set() sleeps the call needs to be deferred
to a workqueue, in which case the actual achieved delays are unknown
(this is a preparation patch for the deferring).

2. Since the callers don't care about the actual achieved delays, allowing
callers to directly pass a value leads to simpler code for most callers.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Tested-by: Yauhen Kharuzhy <jekhor@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Acked-by: Florian Westphal <fw@strlen.de>
Link: https://lore.kernel.org/r/20230510162234.291439-2-hdegoede@redhat.com
Signed-off-by: Lee Jones <lee@kernel.org>

leds: trigger: use RCU to protect the led_cdevs list

Even with the previous commit 27af8e2c90fb
("leds: trigger: fix potential deadlock with libata")
to this file, we still get lockdep unhappy, and Boqun
explained the report here:
https://lore.kernel.org/r/YNA+d1X4UkoQ7g8a@boqun-archlinux

Effectively, this means that the read_lock_irqsave() isn't
enough here because another CPU might be trying to do a
write lock, and thus block the readers.

This is all pretty messy, but it doesn't seem right that
the LEDs framework imposes some locking requirements on
users, in particular we'd have to make the spinlock in the
iwlwifi driver always disable IRQs, even if we don't need
that for any other reason, just to avoid this deadlock.

Since writes to the led_cdevs list are rare (and are done
by userspace), just switch the list to RCU. This costs a
synchronize_rcu() at removal time so we can ensure things
are correct, but that seems like a small price to pay for
getting lock-free iterations and no deadlocks (nor any
locking requirements imposed on users.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Pavel Machek <pavel@ucw.cz>

leds: trigger: fix potential deadlock with libata

We have the following potential deadlock condition:

========================================================
WARNING: possible irq lock inversion dependency detected
5.10.0-rc2+ #25 Not tainted
--------------------------------------------------------
swapper/3/0 just changed the state of lock:
ffff8880063bd618 (&host->lock){-...}-{2:2}, at: ata_bmdma_interrupt+0x27/0x200
but this lock took another, HARDIRQ-READ-unsafe lock in the past:
(&trig->leddev_list_lock){.+.?}-{2:2}

and interrupts could create inverse lock ordering between them.

other info that might help us debug this:
Possible interrupt unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&trig->leddev_list_lock);
local_irq_disable();
lock(&host->lock);
lock(&trig->leddev_list_lock);
<Interrupt>
lock(&host->lock);

*** DEADLOCK ***

no locks held by swapper/3/0.

the shortest dependencies between 2nd lock and 1st lock:
-> (&trig->leddev_list_lock){.+.?}-{2:2} ops: 46 {
HARDIRQ-ON-R at:
lock_acquire+0x15f/0x420
_raw_read_lock+0x42/0x90
led_trigger_event+0x2b/0x70
rfkill_global_led_trigger_worker+0x94/0xb0
process_one_work+0x240/0x560
worker_thread+0x58/0x3d0
kthread+0x151/0x170
ret_from_fork+0x1f/0x30
IN-SOFTIRQ-R at:
lock_acquire+0x15f/0x420
_raw_read_lock+0x42/0x90
led_trigger_event+0x2b/0x70
kbd_bh+0x9e/0xc0
tasklet_action_common.constprop.0+0xe9/0x100
tasklet_action+0x22/0x30
__do_softirq+0xcc/0x46d
run_ksoftirqd+0x3f/0x70
smpboot_thread_fn+0x116/0x1f0
kthread+0x151/0x170
ret_from_fork+0x1f/0x30
SOFTIRQ-ON-R at:
lock_acquire+0x15f/0x420
_raw_read_lock+0x42/0x90
led_trigger_event+0x2b/0x70
rfkill_global_led_trigger_worker+0x94/0xb0
process_one_work+0x240/0x560
worker_thread+0x58/0x3d0
kthread+0x151/0x170
ret_from_fork+0x1f/0x30
INITIAL READ USE at:
lock_acquire+0x15f/0x420
_raw_read_lock+0x42/0x90
led_trigger_event+0x2b/0x70
rfkill_global_led_trigger_worker+0x94/0xb0
process_one_work+0x240/0x560
worker_thread+0x58/0x3d0
kthread+0x151/0x170
ret_from_fork+0x1f/0x30
}
... key at: [<ffffffff83da4c00>] __key.0+0x0/0x10
... acquired at:
_raw_read_lock+0x42/0x90
led_trigger_blink_oneshot+0x3b/0x90
ledtrig_disk_activity+0x3c/0xa0
ata_qc_complete+0x26/0x450
ata_do_link_abort+0xa3/0xe0
ata_port_freeze+0x2e/0x40
ata_hsm_qc_complete+0x94/0xa0
ata_sff_hsm_move+0x177/0x7a0
ata_sff_pio_task+0xc7/0x1b0
process_one_work+0x240/0x560
worker_thread+0x58/0x3d0
kthread+0x151/0x170
ret_from_fork+0x1f/0x30

-> (&host->lock){-...}-{2:2} ops: 69 {
IN-HARDIRQ-W at:
lock_acquire+0x15f/0x420
_raw_spin_lock_irqsave+0x52/0xa0
ata_bmdma_interrupt+0x27/0x200
__handle_irq_event_percpu+0xd5/0x2b0
handle_irq_event+0x57/0xb0
handle_edge_irq+0x8c/0x230
asm_call_irq_on_stack+0xf/0x20
common_interrupt+0x100/0x1c0
asm_common_interrupt+0x1e/0x40
native_safe_halt+0xe/0x10
arch_cpu_idle+0x15/0x20
default_idle_call+0x59/0x1c0
do_idle+0x22c/0x2c0
cpu_startup_entry+0x20/0x30
start_secondary+0x11d/0x150
secondary_startup_64_no_verify+0xa6/0xab
INITIAL USE at:
lock_acquire+0x15f/0x420
_raw_spin_lock_irqsave+0x52/0xa0
ata_dev_init+0x54/0xe0
ata_link_init+0x8b/0xd0
ata_port_alloc+0x1f1/0x210
ata_host_alloc+0xf1/0x130
ata_host_alloc_pinfo+0x14/0xb0
ata_pci_sff_prepare_host+0x41/0xa0
ata_pci_bmdma_prepare_host+0x14/0x30
piix_init_one+0x21f/0x600
local_pci_probe+0x48/0x80
pci_device_probe+0x105/0x1c0
really_probe+0x221/0x490
driver_probe_device+0xe9/0x160
device_driver_attach+0xb2/0xc0
__driver_attach+0x91/0x150
bus_for_each_dev+0x81/0xc0
driver_attach+0x1e/0x20
bus_add_driver+0x138/0x1f0
driver_register+0x91/0xf0
__pci_register_driver+0x73/0x80
piix_init+0x1e/0x2e
do_one_initcall+0x5f/0x2d0
kernel_init_freeable+0x26f/0x2cf
kernel_init+0xe/0x113
ret_from_fork+0x1f/0x30
}
... key at: [<ffffffff83d9fdc0>] __key.6+0x0/0x10
... acquired at:
__lock_acquire+0x9da/0x2370
lock_acquire+0x15f/0x420
_raw_spin_lock_irqsave+0x52/0xa0
ata_bmdma_interrupt+0x27/0x200
__handle_irq_event_percpu+0xd5/0x2b0
handle_irq_event+0x57/0xb0
handle_edge_irq+0x8c/0x230
asm_call_irq_on_stack+0xf/0x20
common_interrupt+0x100/0x1c0
asm_common_interrupt+0x1e/0x40
native_safe_halt+0xe/0x10
arch_cpu_idle+0x15/0x20
default_idle_call+0x59/0x1c0
do_idle+0x22c/0x2c0
cpu_startup_entry+0x20/0x30
start_secondary+0x11d/0x150
secondary_startup_64_no_verify+0xa6/0xab

This lockdep splat is reported after:
commit e918188611f0 ("locking: More accurate annotations for read_lock()")

To clarify:
- read-locks are recursive only in interrupt context (when
in_interrupt() returns true)
- after acquiring host->lock in CPU1, another cpu (i.e. CPU2) may call
write_lock(&trig->leddev_list_lock) that would be blocked by CPU0
that holds trig->leddev_list_lock in read-mode
- when CPU1 (ata_ac_complete()) tries to read-lock
trig->leddev_list_lock, it would be blocked by the write-lock waiter
on CPU2 (because we are not in interrupt context, so the read-lock is
not recursive)
- at this point if an interrupt happens on CPU0 and
ata_bmdma_interrupt() is executed it will try to acquire host->lock,
that is held by CPU1, that is currently blocked by CPU2, so:

* CPU0 blocked by CPU1
* CPU1 blocked by CPU2
* CPU2 blocked by CPU0

*** DEADLOCK ***

The deadlock scenario is better represented by the following schema
(thanks to Boqun Feng <boqun.feng@gmail.com> for the schema and the
detailed explanation of the deadlock condition):

CPU 0: CPU 1: CPU 2:
----- ----- -----
led_trigger_event():
read_lock(&trig->leddev_list_lock);
<workqueue>
ata_hsm_qc_complete():
spin_lock_irqsave(&host->lock);
write_lock(&trig->leddev_list_lock);
ata_port_freeze():
ata_do_link_abort():
ata_qc_complete():
ledtrig_disk_activity():
led_trigger_blink_oneshot():
read_lock(&trig->leddev_list_lock);
// ^ not in in_interrupt() context, so could get blocked by CPU 2
<interrupt>
ata_bmdma_interrupt():
spin_lock_irqsave(&host->lock);

Fix by using read_lock_irqsave/irqrestore() in led_trigger_event(), so
that no interrupt can happen in between, preventing the deadlock
condition.

Apply the same change to led_trigger_blink_setup() as well, since the
same deadlock scenario can also happen in power_supply_update_bat_leds()
-> led_trigger_blink() -> led_trigger_blink_setup() (workqueue context),
and potentially prevent other similar usages.

Link: https://lore.kernel.org/lkml/20201101092614.GB3989@xps-13-7390/
Fixes: eb25cb9956cc ("leds: convert IDE trigger to common disk trigger")
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Pavel Machek <pavel@ucw.cz>

leds: trigger: add support for LED-private device triggers

Some LED controllers may come with an internal HW triggering mechanism
for the LED and the ability to switch between SW control and the
internal HW control. This includes most PHYs, various ethernet switches,
the Turris Omnia LED controller or AXP20X PMIC.

This adds support for registering such triggers.

This code is based on work by Pavel Machek <pavel@ucw.cz> and
Ondřej Jirman <megous@megous.com>.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Acked-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Signed-off-by: Pavel Machek <pavel@ucw.cz>

leds: fix spelling mistake

Fix typo: "Tigger" --> "Trigger"

Signed-off-by: Flavio Suligoi <f.suligoi@asem.it>
Reviewed-by: Alexander Dahl <ada@thorsis.com>
Signed-off-by: Pavel Machek <pavel@ucw.cz>

leds: remove PAGE_SIZE limit of /sys/class/leds/<led>/trigger

Reading /sys/class/leds/<led>/trigger returns all available LED triggers.
However, the size of this file is limited to PAGE_SIZE because of the
limitation for sysfs attribute.

Enabling LED CPU trigger on systems with thousands of CPUs easily hits
PAGE_SIZE limit, and makes it impossible to see all available LED triggers
and which trigger is currently activated.

We work around it here by converting /sys/class/leds/<led>/trigger to
binary attribute, which is not limited by length. This is _not_ good
design, do not copy it.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Dan Murphy <dmurphy@ti.com>A
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Pavel Machek <pavel@ucw.cz>

led: triggers: Fix dereferencing of null pointer

Error was detected by PVS-Studio:
V522 Dereferencing of the null pointer 'led_cdev->trigger' might take place.

Fixes: 2282e125a406 ("leds: triggers: let struct led_trigger::activate() return an error code")
Signed-off-by: Oleh Kravchenko <oleg@kaa.org.ua>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

led: triggers: Fix a memory leak bug

In led_trigger_set(), 'event' is allocated in kasprintf(). However, it is
not deallocated in the following execution if the label 'err_activate' or
'err_add_groups' is entered, leading to memory leaks. To fix this issue,
free 'event' before returning the error.

Fixes: 52c47742f79d ("leds: triggers: send uevent when changing triggers")
Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

led: triggers: Initialize LED_INIT_DEFAULT_TRIGGER if trigger is brought after class

Trigger driver can be initialized after the LED class device driver. In
such case led_trigger_set_default() won't be called and flag
LED_INIT_DEFAULT_TRIGGER should be set from led_trigger_register().

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

led: triggers: Add LED_INIT_DEFAULT_TRIGGER flag

Add the flag LED_INIT_DEFAULT_TRIGGER for indicating that trigger
being set is a default trigger for the LED class device, and
thus it should be initialized with settings provided in the fwnode.

Set the flag in the led_trigger_set_default(). It is expected to be
cleared in the activate() op of a trigger after trigger fwnode
initialization data is parsed and applied. This should happen only
once after LED class device registration, to allow leaving triggers
in the idle state on re-apply and let the users apply their own
settings without interference from the default ones.

Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

led: triggers: Break the for loop after default trigger is found

It is of no avail to continue iterating through registered
triggers in the led_trigger_set_default() after the trigger to set
has been found. Add "break" statement to fix this omission.

Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

leds: triggers: handle .trigger_data and .activated() in the core

This helps keeping these two fields consistent and drivers don't need to
care for this themselves any more.

Note that .activated isn't set to true automatically because that might
confuse some triggers when deactivating (e.g. ledtrig-gpio).

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

leds: triggers: add device attribute support

As many triggers use device attributes, add support for these in
led_trigger_set which allows simplifying the drivers accordingly.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

leds: triggers: let struct led_trigger::activate() return an error code

Given that activating a trigger can fail, let the callback return an
indication. This prevents to have a trigger active according to the
"trigger" sysfs attribute but not functional.

All users are changed accordingly to return 0 for now. There is no intended
change in behaviour.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

leds: triggers: Check return value of kobject_uevent_env()

Log error message if kobject_uevent_env() fails in led_trigger_set().

Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

leds: triggers: Return from led_trigger_set() if there is nothing to do

If led_trigger_set() is called with "trig" argument set to NULL, and there
is no trigger to remove then the function should return immediately so
as to avoid doing unnecessary allocation and sending uevent.

Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Reported-by: Daniel Romell <daro@hms.se>
Acked-by Daniel Romell <daro@hms.se>

leds: do not overflow sysfs buffer in led_trigger_show

Per the documentation, use scnprintf instead of sprintf to ensure there
is never more than PAGE_SIZE bytes of trigger names put into the
buffer.

Signed-off-by: Nathan Sullivan <nathan.sullivan@ni.com>
Signed-off-by: Zach Brown <zach.brown@ni.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

leds: make triggers explicitly non-modular

The Kconfig currently controlling compilation of this code is:

drivers/leds/trigger/Kconfig:menuconfig LEDS_TRIGGERS
drivers/leds/trigger/Kconfig: bool "LED Trigger support"

...meaning that it currently is not being built as a module by anyone.

Lets remove the couple traces of modular infrastructure use, so that
when reading the driver there is no doubt it is builtin-only.

We also delete the MODULE_LICENSE tag etc. since all that information
is already contained at the top of the file in the comments.

We don't replace module.h with init.h since the file doesn't need that.
However it does use EXPORT_SYMBOL, so we add the export.h header.

Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: linux-leds@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

leds: triggers: return error if invalid trigger name is provided via sysfs

If an invalid trigger name is provided via sysfs currently no error
is returned. Therefore it's not possible to determine whether the
trigger was set successfully.
Fix this by returning -EINVAL if no trigger is matched.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

leds: triggers: Allow to switch the trigger to "panic" on a kernel panic

This commit adds a new led_cdev flag LED_PANIC_INDICATOR, which
allows to mark a specific LED to be switched to the "panic"
trigger, on a kernel panic.

This is useful to allow the user to assign a regular trigger
to a given LED, and still blink that LED on a kernel panic.

Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Reviewed-by: Matthias Brugger <mbrugger@suse.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

leds: triggers: simplify led_trigger_store

led_trigger_store can be significantly simplified by using sysfs_streq().

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

leds: core: add managed version of led_trigger_register

Complementing devm_led_classdev_register add a managed version of
led_trigger_register.

I omit a managed version of led_classdev_unregister as the equivalent
devm_led_classdev_unregister isn't used in the kernel as of today.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>

leds: implement sysfs interface locking mechanism

Add a mechanism for locking LED subsystem sysfs interface.
This patch prepares ground for addition of LED Flash Class
extension, whose API will be integrated with V4L2 Flash API.
Such a fusion enforces introducing a locking scheme, which
will secure consistent access to the LED Flash Class device.

The mechanism being introduced allows for disabling LED
subsystem sysfs interface by calling led_sysfs_disable function
and enabling it by calling led_sysfs_enable. The functions
alter the LED_SYSFS_DISABLE flag state and must be called
under mutex lock. The state of the lock is checked with use
of led_sysfs_is_disabled function. Such a design allows for
providing immediate feedback to the user space on whether
the LED Flash Class device is available or is under V4L2 Flash
sub-device control.

Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

leds: make sure we unregister a trigger only once

Currently, we may attempt to unregister a trigger more than once, for
example when we receive two consecutive reboot notifications, or when
we do a regular unregistration plus reboot notification.

This leads to the following error since we try to delete the list node
twice:

[ 2780.254922] WARNING: CPU: 0 PID: 13764 at lib/list_debug.c:53 __list_del_entry+0x3e/0xe0()
[ 2780.265559] list_del corruption, ffffffffa5eb6470->next is LIST_POISON1 (dead000000100100)
[ 2780.271710] Modules linked in:
[ 2780.274156] CPU: 0 PID: 13764 Comm: kworker/0:2 Tainted: G W 3.14.0-next-20140403-sasha-00012-gef5fa7d-dirty #373
[ 2780.283063] Workqueue: events do_poweroff
[ 2780.285644] 0000000000000009 ffff8800330dbb38 ffffffffa34bfa33 0000000000002fe0
[ 2780.291571] ffff8800330dbb88 ffff8800330dbb78 ffffffffa015a37c ffff8800330dbb68
[ 2780.296670] ffffffffa5eb6470 0000000000000000 ffffffffa5eb6400 ffffffffa5ad7430
[ 2780.299756] Call Trace:
[ 2780.301530] dump_stack (lib/dump_stack.c:52)
[ 2780.303802] warn_slowpath_common (kernel/panic.c:418)
[ 2780.306151] warn_slowpath_fmt (kernel/panic.c:433)
[ 2780.308156] __list_del_entry (lib/list_debug.c:51 (discriminator 1))
[ 2780.310800] list_del (lib/list_debug.c:78)
[ 2780.313175] led_trigger_unregister (drivers/leds/led-triggers.c:225)
[ 2780.315599] heartbeat_reboot_notifier (drivers/leds/trigger/ledtrig-heartbeat.c:119)
[ 2780.317247] notifier_call_chain (kernel/notifier.c:95)
[ 2780.320014] __blocking_notifier_call_chain (kernel/notifier.c:316)
[ 2780.323263] blocking_notifier_call_chain (kernel/notifier.c:326)
[ 2780.326096] kernel_power_off (include/linux/kmod.h:95 kernel/reboot.c:153 kernel/reboot.c:179)
[ 2780.327883] do_poweroff (kernel/power/poweroff.c:23)
[ 2780.330748] process_one_work (kernel/workqueue.c:2221 include/linux/jump_label.h:105 include/trace/events/workqueue.h:111 kernel/workqueue.c:2226)
[ 2780.333027] ? process_one_work (include/linux/workqueue.h:186 kernel/workqueue.c:611 kernel/workqueue.c:638 kernel/workqueue.c:2214)
[ 2780.335487] process_scheduled_works (include/linux/list.h:188 kernel/workqueue.c:2277)
[ 2780.337101] worker_thread (kernel/workqueue.c:2352)
[ 2780.338712] ? rescuer_thread (kernel/workqueue.c:2297)
[ 2780.341326] kthread (kernel/kthread.c:219)
[ 2780.343446] ? kthread_create_on_node (kernel/kthread.c:185)
[ 2780.345733] ret_from_fork (arch/x86/kernel/entry_64.S:555)
[ 2780.347168] ? kthread_create_on_node (kernel/kthread.c:185)

Prevent it by making sure we don't attempt to unregister a trigger that
is not in the triggers list.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

drivers/leds: 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.

Cc: Bryan Wu <cooloney@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: linux-leds@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

leds: replace list_for_each with list_for_each_entry

Use the more convenient macro.

Signed-off-by: ZHAO Gang <gamerh2o@gmail.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

leds: led-triggers: Fix checkpatch warnings

Fixes the following type of warnings:
WARNING: Prefer netdev_warn(netdev, ... then dev_warn(dev, ...
then pr_warn(... to printk(KERN_WARNING ...
WARNING: quoted string split across lines

While at it also fix a coding style issue w.r.t braces.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

leds: add led_trigger_rename function

Implements a "led_trigger_rename" function to rename a trigger with
proper locking.

This assumes that led name was originally allocated in non-constant
storage.

Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com>
Cc: Kurt Van Dijck <kurt.van.dijck@eia.be>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

leds: triggers: send uevent when changing triggers

Some triggers create sysfs files when they are enabled. Send a uevent
"change" notification whenever the trigger is changed to allow userspace
processes such as udev to modify permissions on the new files.

A change notification will also be sent during registration of led class
devices or led triggers if the default trigger of an led class device
is found.

(bryan.wu@canonical.com: rename trigger to trig to fix the build error)

Signed-off-by: Colin Cross <ccross@android.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>

leds: delay led_set_brightness if stopping soft-blink

Delay execution of led_set_brightness() if need to stop soft-blink
timer.

This allows led_set_brightness to be called in hard-irq context even if
soft-blink was activated on that LED.

Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>

Revert "leds: use led_set_brightness in led_trigger_event"

This reverts commit a0193cbee0809d65362a0767b2d50306b145b2f5.

The problem with the original commit was that it caused a warning with
the MMC trigger calling del_timer_sync from hard-irq context.

Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com>
Reported-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>

leds: fix sparse warnings due to missing static

drivers/leds/led-core.c:56:6: sparse: symbol 'led_blink_setup' was not declared. Should it be static?
drivers/leds/led-triggers.c:233:6: sparse: symbol 'led_trigger_blink_setup' was not declared. Should it be static?

Reported-by: Fengguang Wu <wfg@linux.intel.com>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>

leds: use led_set_brightness in led_trigger_event

Fix led_trigger_event() to use led_set_brightness() instead of
__led_set_brightness(), so that any pending blink timer is stopped before
setting the new brightness value. Without this fix LED status may be
overridden by a pending timer.

This allows a trigger to use a mix of led_trigger_event(),
led_trigger_blink() and led_trigger_blink_oneshot() without races.

(applied over: leds: Rename led_brightness_set() to led_set_brightness())

Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com>
Cc: Shuah Khan <shuahkhan@gmail.com>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>

leds: Rename led_brightness_set() to led_set_brightness()

Rename leds external interface led_brightness_set() to led_set_brightness().
This is the second phase of the change to reduce confusion between the
leds internal and external interfaces that set brightness. With this change,
now the external interface is led_set_brightness(). The first phase renamed
the internal interface led_set_brightness() to __led_set_brightness().
There are no changes to the interface implementations.

Signed-off-by: Shuah Khan <shuahkhan@gmail.com>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>

leds: Rename led_set_brightness() to __led_set_brightness()

Rename leds internal interface led_set_brightness() to __led_set_brightness()
to reduce confusion between led_set_brightness() and the external interface
led_brightness_set(). led_brightness_set() cancels the timer and then calls
led_set_brightness().

Signed-off-by: Shuah Khan <shuahkhan@gmail.com>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>

leds: add oneshot blink functions

Add two new functions, led_blink_set_oneshot and
led_trigger_blink_oneshot, to be used by triggers for one-shot blink of
led devices.

This is implemented extending the existing software-blink code, and uses
the same timer and handler function.

The behavior of the code is to do a blink-on, blink-off sequence when
the function is called, ignoring other calls until the sequence is
completed so that the leds keep blinking at constant rate if the
functions are called repeatedly.

This is meant to be used by drivers which needs to trigger on sporadic
event, but doesn't have clear busy/idle trigger points.

After the blink sequence the led remains off. This behavior can be
inverted setting the "invert" argument, which blink the led off, than on
and leave the led on after the sequence.

(bryan.wu@canonical.com: rebase to commit 'leds: don't disable blinking
when writing the same value to delay_on or delay_off')

Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com>
Acked-by: Shuah Khan <shuahkhan@gmail.com>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>

led-triggers: rename *trigger to *trig for unified naming scheme

No functional change.

Signed-off-by: Bryan Wu <bryan.wu@canonical.com>

driver-core: remove sysdev.h usage.

The sysdev.h file should not be needed by any in-kernel code, so remove
the .h file from these random files that seem to still want to include
it.

The sysdev code will be going away soon, so this include needs to be
removed no matter what.

Cc: Jiandong Zheng <jdzheng@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: David Brown <davidb@codeaurora.org>
Cc: Daniel Walker <dwalker@fifo99.com>
Cc: Bryan Huntsman <bryanh@codeaurora.org>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: "Venkatesh Pallipadi
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>

drivers/leds/led-triggers.c: fix memory leak

The memory for struct led_trigger should be kfreed in the
led_trigger_register() error path. Also this function should return NULL
on error.

Signed-off-by: Masakazu Mokuno <mokuno@sm.sony.co.jp>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

leds: Add ability to blink via simple trigger

As blink API is now available, it's possible to add ability to blink via
simple trigger.

Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>

led-class: always implement blinking

Currently, blinking LEDs can be awkward because it is not guaranteed that
all LEDs implement blinking. The trigger that wants it to blink then
needs to implement its own timer solution.

Rather than require that, add led_blink_set() API that triggers can use.
This function will attempt to use hw blinking, but if that fails
implements a timer for it. To stop blinking again, brightness_set() also
needs to be wrapped into API that will stop the software blink.

As a result of this, the timer trigger becomes a very trivial one, and
hopefully we can finally see triggers using blinking as well because it's
always easy to use.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Richard Purdie <rpurdie@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

leds: Prevent multiple LED triggers with the same name

Signed-off-by: Adam Nielsen <a.nielsen@shikadi.net>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>

leds: Ensure led->trigger is set earlier

Make sure led->trigger is valid before calling trigger->activate

Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>

leds: Cleanup various whitespace and code style issues

Break the lines which were more than 80 characters into more
lines; replace SPACEs with TABs; correct ident at switch-case;
change character encoding from ISO-8859-2 to UTF-8.

The order of the functions in led-triggers.c changed in order
the similar functions can still be together under titles
"Used by LED Class", "LED Trigger Interface" and "Simple
LED Tigger Interface" as was grouped before when exported
with EXPORT_SYMBOL.

Signed-off-by: Márton Németh <nm127@freemail.hu>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>

leds: disable triggers on brightness set

Disable any active triggers when the brightness attribute is
set to zero.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Márton Németh <nm127@freemail.hu>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>

leds: Fix leds_list_lock locking issues

Covert leds_list_lock to a rw_sempahore to match previous LED trigger
locking fixes, fixing lock ordering.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>

leds: Fix led trigger locking bugs

Convert part of the led trigger core from rw spinlocks to rw
semaphores. We're calling functions which can sleep from invalid
contexts otherwise. Fixes bug #9264.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>

leds: Convert from struct class_device to struct device

Convert the LEDs class from struct class_device to struct device
since class_device is scheduled for removal.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>

leds: Add warning printks in error paths

Add warning printks if led_trigger_register_simple() fails.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>

leds: Fix trigger unregister_simple if register_simple fails

Fix led_trigger_unregister_simple to handle the case where
led_trigger_register_simple fails, avoiding a NULL pointer
dereference.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>

[PATCH] leds: turn LED off when changing triggers

I was playing with LED triggers when I noticed that changing from heartbeat
(or ide-disk) to "none" at the right moment would leave the LED stuck on.
This is easy to reproduce by doing "find / >/dev/null" with the ide-disk
trigger enabled and then switching to "none".

Here is a patch that fixes the problem by explicitly turning the LED off
after removing the existing trigger.

Signed-off-by: Paul Collins <paul@ondioline.org>
Acked-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Remove obsolete #include <linux/config.h>

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

[PATCH] spin/rwlock init cleanups

locking init cleanups:

- convert " = SPIN_LOCK_UNLOCKED" to spin_lock_init() or DEFINE_SPINLOCK()
- convert rwlocks in a similar manner

this patch was generated automatically.

Motivation:

- cleanliness
- lockdep needs control of lock initialization, which the open-coded
variants do not give
- it's also useful for -rt and for lock debugging in general

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] LED: add LED trigger tupport

Add support for LED triggers to the LED subsystem. "Triggers" are events
which change the state of an LED. Two kinds of trigger are available, simple
ones which can be added to exising code with minimum disruption and complex
ones for implementing new or more complex functionality.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>