media: dvb-usb: nova-t-usb2: use an enum for the device number

The device number is currently a value that needs to be the same
on two separate tables, but the code doesn't actually enforce it,
leading to errors as boards get added or removed.

Fix it by using an enum.

Link: https://lore.kernel.org/linux-media/58f1a356b7b75bbefef3aa07cd99896c446df32f.1648499509.git.mchehab@kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

media: dvb-usb: fix uninit-value in dvb_usb_adapter_dvb_init

If dibusb_read_eeprom_byte fails, the mac address is not initialized.
And nova_t_read_mac_address does not handle this failure, which leads to
the uninit-value in dvb_usb_adapter_dvb_init.

Fix this by handling the failure of dibusb_read_eeprom_byte.

Reported-by: syzbot+e27b4fd589762b0b9329@syzkaller.appspotmail.com
Fixes: 786baecfe78f ("[media] dvb-usb: move it to drivers/media/usb/dvb-usb")
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: docs: move driver-specific info to driver-api

Those documents don't really describe the driver API.

Instead, they contain development-specific information.

Yet, as the main index file describes the content of it as:

"how specific kernel subsystems work
from the point of view of a kernel developer"

It seems to be the better fit.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 372

Based on 1 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 as published by
the free software foundation version 2

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 135 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531081036.435762997@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

media: dvb: point to the location of the old README.dvb-usb file

This file got renamed, but the references still point to the
old place.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Jonathan Corbet <corbet@lwn.net>

[media] nova-t-usb2: handle error code on RC query

There's no sense on decoding and generating a RC key code if
there was an error on the URB control message.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] nova-t-usb2: don't do DMA on stack

The USB control messages require DMA to work. We cannot pass
a stack-allocated buffer, as it is not warranted that the
stack would be into a DMA enabled area.

Reviewed-by: Patrick Boettcher <patrick.boettcher@posteo.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

[media] media: change email address

Soon my dibcom.fr/parrot.com-address won't respond anymore.
Thus I'm replacing it. And, while being at it,
let's adapt some other (old) email-addresses as well.

Signed-off-by: Patrick Boettcher <patrick.boettcher@posteo.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] dvb-usb: move it to drivers/media/usb/dvb-usb

As media/dvb will be removed, move it to a proper place.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>