Commit Graph

632 Commits

Author SHA1 Message Date
Sean Young 4f253cecf8 [media] redrat3: make hardware timeout configurable
Instead of hardcoding a timeout, let userspace change it dynamically
by adding a s_timeout ops.

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-15 12:01:46 -03:00
Sean Young 25da661a14 [media] redrat3: fix timeout handling
The redrat3 sends an usb packet to the host either when the minimum pause
or the timeout occurs, so we can always add a trailing space in our
processing.

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-15 12:00:16 -03:00
Sean Young 14d8188aab [media] rc: make s_tx_carrier consistent
LIRC_SET_SEND_CARRIER should return 0 on success or -errno.

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-15 11:54:23 -03:00
Sean Young 20f5a827cf [media] rc: make s_tx_mask consistent
When s_tx_mask is given an invalid bitmask, the number of transmitters
should be returned. See the LIRC_SET_TRANSMITTER_MASK lirc ioctl
documentation.

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-15 11:46:55 -03:00
Heiner Kallweit 5cac1f67ea [media] rc: nuvoton: fix hang if chip is configured for alternative EFM IO address
If a system configures the Nuvoton chip to use the alternative
EFM IO address (CR_EFIR2) then after probing the primary EFM IO
address (CR_EFIR) this region is not released.

If a driver for another function of the Nuvoton Super I/O
chip uses the same probing mechanism then it will hang if
loaded after the nuvoton-cir driver.
This was reported for the nct6775 hwmon driver.

Fix this by properly releasing the region after probing CR_EFIR.
This regression was introduced with kernel 4.6 so cc it to stable.

Reported-by: Antti Seppälä <a.seppala@gmail.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Tested-by: Antti Seppälä <a.seppala@gmail.com>
Cc: <stable@vger.kernel.org> # 4.6.x-
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-13 15:49:01 -03:00
Andi Shyti 273b902a5b [media] lirc_dev: use LIRC_CAN_REC() define to check if the device can receive
The LIRC_CAN_REC() returns a boolean "flag & LIRC_CAN_REC_MASK"
to check whether the device can receive data.

Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-13 15:29:03 -03:00
Andi Shyti 8e5fa4c67d [media] lirc_dev: fix potential segfault
When opening or closing a lirc character device, the framework
provides to the user the possibility to keep track of opening or
closing of the device by calling two functions:

 - set_use_inc() when opening the device
 - set_use_dec() when closing the device

if those are not set by the lirc user, the system segfaults.
Check the pointer value before calling the above functions.

Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-13 15:28:25 -03:00
Andi Shyti 62e92682c0 [media] lirc_dev: extremely trivial comment style fix
Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-13 15:27:16 -03:00
Andi Shyti b408809487 [media] lirc_dev: fix error return value
If ioctl is called, it cannot be a case of invalid system call
number (ENOSYS), that is a ENOTTY case which means that the
device doesn't support that specific ioctl command.

So, replace ENOSYS with ENOTTY.

Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-13 15:26:52 -03:00
Andi Shyti 9675ee5a8e [media] lirc_dev: fix variable constant comparisons
When comparing a variable with a constant, the comparison should
start from the variable and not from the constant. It's also
written in the human DNA.

Swap the terms of comparisons whenever the constant comes first
and fix the following checkpatch warning:

  WARNING: Comparisons should place the constant on the right side of the test

Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-13 15:25:41 -03:00
Andi Shyti 14db9fc2d4 [media] lirc_dev: merge three if statements in only one
The three if statements check the same thing, merge them in only
one statement.

Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-13 15:24:28 -03:00
Andi Shyti 6ab86d2aa0 [media] lirc_dev: remove double if ... else statement
There are two if ... else which check the same thing in different
part of the code, they can be merged in a single check.

Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-13 15:09:05 -03:00
Andi Shyti 19e565397c [media] lirc_dev: simplify if statement in lirc_add_to_buf
The whole function is inside an 'if' statement
("if (ir->d.add_to_buf)").

Check the opposite of that statement at the beginning and exit,
this way we can have one level less of indentation.

Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-13 15:06:29 -03:00
Andi Shyti 7fe579d29f [media] lirc_dev: do not use goto to create loops
... use "do .. while" instead.

Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-13 15:01:13 -03:00
Andi Shyti 54fcecafe5 [media] lirc_dev: simplify goto paths
The code can be rearranged so that some goto paths can be removed

Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-13 14:59:19 -03:00
Andi Shyti 3fac031460 [media] lirc_dev: replace printk with pr_* or dev_*
This patch mutes also all the checkpatch warnings related to
printk.

Reword all the printouts so that the string doesn't need to be
split, which fixes the following checkpatch warning:

  WARNING: quoted string split across lines

Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-13 14:58:41 -03:00
Andi Shyti fe084c7eff [media] lirc_dev: remove unnecessary debug prints
Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-13 14:56:26 -03:00
Andi Shyti 70143984dd [media] lirc_dev: allow bufferless driver registration
Transmitters don't necessarily need to have a FIFO managed buffer
for their transfers.

When registering the driver, before allocating the buffer, check
whether the device is a transmitter or receiver. Allocate the
buffer only for receivers.

Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-13 14:54:58 -03:00
Andi Shyti 6fa99e1af1 [media] lirc_dev: place buffer allocation on separate function
During the driver registration, move the buffer allocation on a
separate function.

Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-13 14:52:36 -03:00
Jonathan McDowell a4d020e97d [media] Convert Wideview WT220 DVB USB driver to rc-core
Converts the dtt200u DVB USB driver over to the rc-core
infrastructure for its handling of IR remotes. This device can receive
generic NEC / NEC Extended signals and the switch to the newer core
enables the easy use of tools such as ir-keytable to modify the active
key map.

Signed-off-by: Jonathan McDowell <noodles@earth.li>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-09 12:10:33 -03:00
Jonathan McDowell bbdb34c90a [media] Fix RC5 decoding with Fintek CIR chipset
Fix RC5 decoding with Fintek CIR chipset

Commit e87b540be2 tightened up the RC5
decoding by adding a check for trailing silence to ensure a valid RC5
command had been received. Unfortunately the trailer length checked was
10 units and the Fintek CIR device does not want to provide details of a
space longer than 6350us. This meant that RC5 remotes working on a
Fintek setup on 3.16 failed on 3.17 and later. Fix this by shortening
the trailer check to 6 units (allowing for a previous space in the
received remote command).

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=117221

Signed-off-by: Jonathan McDowell <noodles@earth.li>
Cc: stable@vger.kernel.org
Signed-off-by: David Härdeman <david@hardeman.nu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-09 11:47:28 -03:00
Kamil Debski 7b2cd0d8da [media] rc-cec: Add HDMI CEC keymap module
Add the keymap module for HDMI CEC remote control commands.

Signed-off-by: Kamil Debski <kamil@wypas.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-08 18:26:45 -03:00
Mauro Carvalho Chehab cbb5c8355a Merge branch 'topic/cec' into patchwork
* topic/cec:
  [media] DocBook/media: add CEC documentation
  [media] s5p_cec: get rid of an unused var
  [media] move s5p-cec to staging
  [media] vivid: add CEC emulation
  [media] cec: s5p-cec: Add s5p-cec driver
  [media] cec: adv7511: add cec support
  [media] cec: adv7842: add cec support
  [media] cec: adv7604: add cec support
  [media] cec: add compat32 ioctl support
  [media] cec/TODO: add TODO file so we know why this is still in staging
  [media] cec: add HDMI CEC framework (api)
  [media] cec: add HDMI CEC framework (adapter)
  [media] cec: add HDMI CEC framework (core)
  [media] cec-funcs.h: static inlines to pack/unpack CEC messages
  [media] cec.h: add cec header
  [media] cec-edid: add module for EDID CEC helper functions
  [media] cec.txt: add CEC framework documentation
  [media] rc: Add HDMI CEC protocol handling
2016-07-08 18:16:10 -03:00
Heiner Kallweit 241d9bb342 [media] media: rc: nuvoton: remove two unused elements in struct nvt_dev
These two fields are not used and can be removed.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-08 17:19:35 -03:00
Heiner Kallweit d1e3e574d5 [media] media: rc: nuvoton: remove unneeded check in nvt_get_rx_ir_data
If the logical device is disabled then it can not generate interrupts.
Therefore this check is not needed.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-08 17:19:07 -03:00
Heiner Kallweit 228942efdb [media] media: rc: nuvoton: simplify interrupt handling code
Simplify interupt handling code.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-08 17:18:12 -03:00
Heiner Kallweit e5283f5f1f [media] media: rc: nuvoton: remove study states
Study states have never been used and are not needed. Remove them.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-08 17:17:47 -03:00
Heiner Kallweit bdd36bd975 [media] media: rc: nuvoton: remove unneeded code in nvt_process_rx_ir_data
The definition of rawir includes the initialization already.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-08 17:17:12 -03:00
Heiner Kallweit 7ac7b02345 [media] media: rc: nuvoton: simplify a few functions
Simplify a few functions.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-08 17:16:31 -03:00
Heiner Kallweit cb359a863a [media] media: rc: nuvoton: remove wake states
Wake states have never been in use and now that we can set the
wakeup sequence via sysfs there's in general no need for them.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-08 17:14:32 -03:00
Heiner Kallweit 594ccee6f0 [media] media: rc: nuvoton: clean up initialization of wakeup registers
The registers defining wakeup sequence handling are set when the
wakeup sequence is set via sysfs. There's no need to initialize them
otherwise.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-08 17:13:37 -03:00
Heiner Kallweit cb48b3698f [media] media: rc: nuvoton: remove interrupt handling for wakeup
There is a rudimentary ISR for handling interrupts generated by the
wakeup part of the chip. Interrupts however have never been enabled
in the wakeup part.
Also, now that we can set the wakeup sequence via sysfs, there's in
general no need to enable interrupts in the wakeup part.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-08 17:05:38 -03:00
Heiner Kallweit 398d9da83f [media] media: rc: nuvoton: fix rx fifo overrun handling
To detect a rx fifo overrun it's checked whether the number of elements
in the chip fifo exceeds the fifo size. This check can never return true
and is wrong.
Instead we should generate an interrupt if the fifo overruns.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-08 17:03:41 -03:00
Hans Verkuil d54fc3bbc2 [media] rc-main: fix kernel oops after unloading keymap module
When the rc_map table is created the char pointer of the name of the keymap
is copied to the rc_map->name field. However, this pointer points to memory
from the keymap module itself.

Since these keymap modules are not refcounted, that means anyone can call
rmmod to unload that module. Which is not a big deal because the contents of
the map is all copied to rc_map, except for the keymap name.

So after a keymap module is unloaded the name pointer has become stale. Unloading
the rc-core module will now cause a kernel oops in rc_dev_uevent().

The solution is to kstrdup the name so there are no more references to the
keymap module remaining.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-07-08 16:16:53 -03:00
Kamil Debski ff42c8aa6c [media] rc: Add HDMI CEC protocol handling
Add handling of remote control events coming from the HDMI CEC bus
and the new protocol required for that.

Signed-off-by: Kamil Debski <kamil@wypas.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-06-22 08:35:55 -03:00
Max Kellermann 47cae1e1cf [media] drivers/media/rc: postpone kfree(rc_dev)
CONFIG_DEBUG_KOBJECT_RELEASE found this bug.

Signed-off-by: Max Kellermann <max@duempel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2016-05-07 11:21:04 -03:00
Olli Salonen 1869384387 [media] mceusb: add support for SMK eHome receiver
Add USB ID of SMK RXX6000 series IR receiver. Often branded as
Lenovo receiver.

Signed-off-by: Olli Salonen <olli.salonen@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2016-05-07 10:30:46 -03:00
Olli Salonen e186613aed [media] mceusb: add support for Adaptec eHome receiver
New USB ID for Adaptec eHome receiver in some HP laptops.

Signed-off-by: Olli Salonen <olli.salonen@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2016-05-07 10:30:17 -03:00
Heiner Kallweit 36ac2f3259 [media] media: rc: remove unneeded mutex in rc_register_device
Access to dev->initialized is atomic and dev->initialized isn't
accessed in any other code protected by this mutex.
Therefore we don't need to get the mutex here.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2016-05-07 10:29:49 -03:00
Rasmus Villemoes 869f076bd6 [media] ati_remote: avoid fragile snprintf use
Passing overlapping source and destination to snprintf is
fragile. Replace with a single (mostly) equivalent call. If one wants
to preserve the space preceding udev->product whether or not there was
a manufacturer, just remove udev->manufacturer from the && expression.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2016-05-07 10:27:16 -03:00
Mauro Carvalho Chehab eef8fc374c [media] mceusb: use %*ph for small buffer dumps
It makes the printk cleaner. As a side efect, it also fixes those smatch
warnings:
	drivers/media/rc/mceusb.c:590 mceusb_dev_printdata() warn: argument 6 to %02x specifier has type 'char'
	drivers/media/rc/mceusb.c:590 mceusb_dev_printdata() warn: argument 7 to %02x specifier has type 'char'

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2016-03-10 13:37:44 -03:00
Heiner Kallweit 02212001c9 [media] media: rc: nuvoton: switch attribute wakeup_data to text
Switch attribute wakeup_data from binary to a text attribute.
This makes it easier to handle in userspace and allows to
use the output of tools like mode2 almost as is to set a
wakeup sequence.
Changing to a text format and values in microseconds also
makes the userspace interface independent of the setting of
SAMPLE_PERIOD in the driver.

In addition document the new sysfs attribute in
Documentation/ABI/testing/sysfs-class-rc-nuvoton.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2016-03-05 08:22:03 -03:00
Emilio López ea05e8b4ec [media] rc: sunxi-cir: support module autoloading
MODULE_DEVICE_TABLE() is missing, so the module isn't auto-loading on
systems supporting infrared. This commit adds the missing line so it
works out of the box when built as a module and running on a sunxi
system with an infrared receiver.

Signed-off-by: Emilio López <emilio.lopez@collabora.co.uk>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2016-03-03 12:42:34 -03:00
Sean Young a40973ff10 [media] igorplugusb: fix leaks in error path
Since rc_allocate_device() uses kmalloc, it can returns NULL,
so need to check,  otherwise, NULL derefenrece can happen.

Reported-by: Insu Yun <wuninsu@gmail.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2016-03-03 11:44:29 -03:00
Philippe Valembois b21d29e08c [media] Fix AverMedia RM-KS remote keymap
Fix AverMedia RM-KS keymap using user guide to meet LinuxTV wiki rules.
The remote command didn't seem to change in itself since its creation: it's
just to make keys more standard and remove the FIXME.

Signed-off-by: Philippe Valembois <lephilousophe@users.sourceforge.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2016-03-03 08:33:41 -03:00
Heiner Kallweit 449c1fcd86 [media] media: rc: nuvoton: support reading / writing wakeup sequence via sysfs
This patch adds a binary attribute /sys/class/rc/rc?/wakeup_data which
allows to read / write the wakeup sequence.

In combination with the core extension for exposing the most recent raw
packet this allows to easily define and set a wakeup sequence.

At least on my Zotac CI321 the BIOS resets the wakeup sequence at each boot
to a factory default. Therefore I use a udev rule
SUBSYSTEM=="rc", DRIVERS=="nuvoton-cir", ACTION=="add", RUN+="<script>"
with the script basically doing
cat <stored wakeup sequence> >/sys${DEVPATH}/wakeup_data

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2016-03-03 08:28:41 -03:00
Mauro Carvalho Chehab 078600f514 [media] rc-core: allow calling rc_open with device not initialized
The device initialization completes only after calling
input_register_device(). However, rc_open() can be called while
the device is being registered by the input/evdev core. So, we
can't expect that rc_dev->initialized to be true.

Change the logic to don't require initialized == true at rc_open
and change the type of initialized to be atomic.

this way, we can check for it earlier where it is really needed,
without needing to lock the mutex just for testing it.

Tested with nuvoton_cir driver on a NUC5i7RYB with CIR integrated on it.

Reported-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2016-03-03 06:16:14 -03:00
Mauro Carvalho Chehab b64e10f3df [media] lirc_dev: avoid double mutex unlock
We can only unlock if mutex_lock() succeeds.

Fixes the following warning:
	drivers/media/rc/lirc_dev.c:535 lirc_dev_fop_close() error: double unlock 'mutex:&lirc_dev_lock'

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2016-03-01 12:04:48 -03:00
Mauro Carvalho Chehab fe28f5de11 [media] ati_remote: Put timeouts at the accel array
Instead of having the timeouts hardcoded, and getting only the
accel value from the array, put everything in the same place.

That simplifies the logic.

As a side effect, it also cleans several smatch errors:
	include/linux/jiffies.h:359:41: error: strange non-value function or array
	include/linux/jiffies.h:361:42: error: strange non-value function or array
(one per time_after/time_before line)

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2016-03-01 12:02:32 -03:00
Mauro Carvalho Chehab c73bbaa4ec [media] rc-core: don't lock device at rc_register_device()
The mutex lock at rc_register_device() was added by commit 08aeb7c9a4
("[media] rc: add locking to fix register/show race").

It is meant to avoid race issues when trying to open a sysfs file while
the RC register didn't complete.

Adding a lock there causes troubles, as detected by the Kernel lock
debug instrumentation at the Kernel:

    ======================================================
    [ INFO: possible circular locking dependency detected ]
    4.5.0-rc3+ #46 Not tainted
    -------------------------------------------------------
    systemd-udevd/2681 is trying to acquire lock:
     (s_active#171){++++.+}, at: [<ffffffff8171a115>] kernfs_remove_by_name_ns+0x45/0xa0

    but task is already holding lock:
     (&dev->lock){+.+.+.}, at: [<ffffffffa0724def>] rc_register_device+0xb2f/0x1450 [rc_core]

    which lock already depends on the new lock.

    the existing dependency chain (in reverse order) is:

    -> #1 (&dev->lock){+.+.+.}:
           [<ffffffff8124817d>] lock_acquire+0x13d/0x320
           [<ffffffff822de966>] mutex_lock_nested+0xb6/0x860
           [<ffffffffa0721f2b>] show_protocols+0x3b/0x3f0 [rc_core]
           [<ffffffff81cdaba5>] dev_attr_show+0x45/0xc0
           [<ffffffff8171f1b3>] sysfs_kf_seq_show+0x203/0x3c0
           [<ffffffff8171a6a1>] kernfs_seq_show+0x121/0x1b0
           [<ffffffff81617c71>] seq_read+0x2f1/0x1160
           [<ffffffff8171c911>] kernfs_fop_read+0x321/0x460
           [<ffffffff815abc20>] __vfs_read+0xe0/0x3d0
           [<ffffffff815ae90e>] vfs_read+0xde/0x2d0
           [<ffffffff815b1d01>] SyS_read+0x111/0x230
           [<ffffffff822e8636>] entry_SYSCALL_64_fastpath+0x16/0x76

    -> #0 (s_active#171){++++.+}:
           [<ffffffff81244f24>] __lock_acquire+0x4304/0x5990
           [<ffffffff8124817d>] lock_acquire+0x13d/0x320
           [<ffffffff81717d3a>] __kernfs_remove+0x58a/0x810
           [<ffffffff8171a115>] kernfs_remove_by_name_ns+0x45/0xa0
           [<ffffffff81721592>] remove_files.isra.0+0x72/0x190
           [<ffffffff8172174b>] sysfs_remove_group+0x9b/0x150
           [<ffffffff81721854>] sysfs_remove_groups+0x54/0xa0
           [<ffffffff81cd97d0>] device_remove_attrs+0xb0/0x140
           [<ffffffff81cdb27c>] device_del+0x38c/0x6b0
           [<ffffffffa0724b8b>] rc_register_device+0x8cb/0x1450 [rc_core]
           [<ffffffffa1326a7b>] dvb_usb_remote_init+0x66b/0x14d0 [dvb_usb]
           [<ffffffffa1321c81>] dvb_usb_device_init+0xf21/0x1860 [dvb_usb]
           [<ffffffffa13517dc>] dib0700_probe+0x14c/0x410 [dvb_usb_dib0700]
           [<ffffffff81dbb1dd>] usb_probe_interface+0x45d/0x940
           [<ffffffff81ce7e7a>] driver_probe_device+0x21a/0xc30
           [<ffffffff81ce89b1>] __driver_attach+0x121/0x160
           [<ffffffff81ce21bf>] bus_for_each_dev+0x11f/0x1a0
           [<ffffffff81ce6cdd>] driver_attach+0x3d/0x50
           [<ffffffff81ce5df9>] bus_add_driver+0x4c9/0x770
           [<ffffffff81cea39c>] driver_register+0x18c/0x3b0
           [<ffffffff81db6e98>] usb_register_driver+0x1f8/0x440
           [<ffffffffa074001e>] dib0700_driver_init+0x1e/0x1000 [dvb_usb_dib0700]
           [<ffffffff810021b1>] do_one_initcall+0x141/0x300
           [<ffffffff8144d8eb>] do_init_module+0x1d0/0x5ad
           [<ffffffff812f27b6>] load_module+0x6666/0x9ba0
           [<ffffffff812f5fe8>] SyS_finit_module+0x108/0x130
           [<ffffffff822e8636>] entry_SYSCALL_64_fastpath+0x16/0x76

    other info that might help us debug this:

     Possible unsafe locking scenario:

           CPU0                    CPU1
           ----                    ----
      lock(&dev->lock);
                                   lock(s_active#171);
                                   lock(&dev->lock);
      lock(s_active#171);

     *** DEADLOCK ***

    3 locks held by systemd-udevd/2681:
     #0:  (&dev->mutex){......}, at: [<ffffffff81ce8933>] __driver_attach+0xa3/0x160
     #1:  (&dev->mutex){......}, at: [<ffffffff81ce8941>] __driver_attach+0xb1/0x160
     #2:  (&dev->lock){+.+.+.}, at: [<ffffffffa0724def>] rc_register_device+0xb2f/0x1450 [rc_core]

In this specific case, some error happened during device init,
causing IR to be disabled.

Let's fix it by adding a var that will tell when the device is
initialized. Any calls before that will return a -EINVAL.

That should prevent the race issues.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2016-02-16 08:40:41 -02:00