Commit graph

19 commits

Author SHA1 Message Date
Heiner Kallweit
74d47d75be [media] rc: refactor raw handler kthread
I think we can get rid of the spinlock protecting the kthread from being
interrupted by a wakeup in certain parts.
Even with the current implementation of the kthread the only lost wakeup
scenario could happen if the wakeup occurs between the kfifo_len check
and setting the state to TASK_INTERRUPTIBLE.

In the changed version we could lose a wakeup if it occurs between
processing the fifo content and setting the state to TASK_INTERRUPTIBLE.
This scenario is covered by an additional check for available events in
the fifo and setting the state to TASK_RUNNING in this case.

In addition the changed version flushes the kfifo before ending
when the kthread is stopped.

With this patch we gain:
- Get rid of the spinlock
- Simplify code
- Don't grep / release the mutex for each individual event but just once
  for the complete fifo content. This reduces overhead if a driver e.g.
  triggers processing after writing the content of a hw fifo to the kfifo.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-01-30 11:46:55 -02:00
Heiner Kallweit
37e90a220a [media] rc: ir-raw: change type of available_protocols to atomic64_t
Changing available_protocols to atomic64_t allows to get rid of the
mutex protecting access to the variable. This helps to simplify
the code.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-10-24 18:16:06 -02:00
Heiner Kallweit
033919e0f8 [media] media: rc: fix deadlock when module ir_lirc_codec is removed
When removing module ir_lirc_codec I got this deadlock warning.
Fix this by introducing a separate mutex to protect access
to available_protocols instead of using ir_raw_handler_lock
for this purpose.

======================================================
[ INFO: possible circular locking dependency detected ]
4.7.0-next-20160729 #1 Not tainted
-------------------------------------------------------
rmmod/2542 is trying to acquire lock:
 (&dev->lock){+.+.+.}, at: [<ffffffffa03b1267>]
			ir_raw_handler_unregister+0x77/0xd0 [rc_core]

but task is already holding lock:
 (ir_raw_handler_lock){+.+.+.}, at: [<ffffffffa03b1212>]
			ir_raw_handler_unregister+0x22/0xd0 [rc_core]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (ir_raw_handler_lock){+.+.+.}:
       [<ffffffff810ab1f2>] lock_acquire+0xb2/0x1e0
       [<ffffffff815c087f>] mutex_lock_nested+0x5f/0x360
       [<ffffffffa03b1403>] ir_raw_get_allowed_protocols+0x13/0x30 [rc_core]
       [<ffffffffa03af8ea>] store_protocols+0x2fa/0x480 [rc_core]
       [<ffffffff8143e143>] dev_attr_store+0x13/0x20
       [<ffffffff81213c50>] sysfs_kf_write+0x40/0x50
       [<ffffffff81212f60>] kernfs_fop_write+0x150/0x1e0
       [<ffffffff81197613>] __vfs_write+0x23/0x120
       [<ffffffff81198740>] vfs_write+0xb0/0x190
       [<ffffffff81199a34>] SyS_write+0x44/0xa0
       [<ffffffff815c55a5>] entry_SYSCALL_64_fastpath+0x18/0xa8

-> #0 (&dev->lock){+.+.+.}:
       [<ffffffff810aac8c>] __lock_acquire+0x10fc/0x1270
       [<ffffffff810ab1f2>] lock_acquire+0xb2/0x1e0
       [<ffffffff815c087f>] mutex_lock_nested+0x5f/0x360
       [<ffffffffa03b1267>] ir_raw_handler_unregister+0x77/0xd0 [rc_core]
       [<ffffffffa03c8c05>] ir_lirc_codec_exit+0x10/0x12 [ir_lirc_codec]
       [<ffffffff810e1b88>] SyS_delete_module+0x168/0x220
       [<ffffffff815c55a5>] entry_SYSCALL_64_fastpath+0x18/0xa8

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(ir_raw_handler_lock);
                               lock(&dev->lock);
                               lock(ir_raw_handler_lock);
  lock(&dev->lock);

 *** DEADLOCK ***

1 lock held by rmmod/2542:
 #0:  (ir_raw_handler_lock){+.+.+.}, at: [<ffffffffa03b1212>]
			ir_raw_handler_unregister+0x22/0xd0 [rc_core]

stack backtrace:
CPU: 0 PID: 2542 Comm: rmmod Not tainted 4.7.0-next-20160729 #1
Hardware name: ZOTAC ZBOX-CI321NANO/ZBOX-CI321NANO, BIOS B246P105 06/01/2015
 0000000000000000 ffff88006e607cc0 ffffffff812715f5 ffffffff8232b230
 ffffffff8232b230 ffff88006e607d00 ffffffff810a846e 00000000790107f0
 ffff880079010818 ffff8800790107f0 1efeb9f4f0dd2e6f ffff880079010000
Call Trace:
 [<ffffffff812715f5>] dump_stack+0x68/0x93
 [<ffffffff810a846e>] print_circular_bug+0x1be/0x210
 [<ffffffff810aac8c>] __lock_acquire+0x10fc/0x1270
 [<ffffffff810bcead>] ? debug_lockdep_rcu_enabled+0x1d/0x20
 [<ffffffff810ab1f2>] lock_acquire+0xb2/0x1e0
 [<ffffffffa03b1267>] ? ir_raw_handler_unregister+0x77/0xd0 [rc_core]
 [<ffffffff815c087f>] mutex_lock_nested+0x5f/0x360
 [<ffffffffa03b1267>] ? ir_raw_handler_unregister+0x77/0xd0 [rc_core]
 [<ffffffff810a980e>] ? trace_hardirqs_on_caller+0xee/0x1b0
 [<ffffffffa03b1267>] ir_raw_handler_unregister+0x77/0xd0 [rc_core]
 [<ffffffffa03c8c05>] ir_lirc_codec_exit+0x10/0x12 [ir_lirc_codec]
 [<ffffffff810e1b88>] SyS_delete_module+0x168/0x220
 [<ffffffff815c55a5>] entry_SYSCALL_64_fastpath+0x18/0xa8

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2016-09-22 11:23:13 -03:00
Heiner Kallweit
464254e5db [media] media: rc: raw: improve FIFO handling
The FIFO is used for ir_raw_event records, however for some historic
reason the FIFO is used on a per byte basis. IMHO this adds unneeded
complexity. Therefore set up the FIFO for ir_raw_event records.

This also allows to define the FIFO statically as part of
ir_raw_event_ctrl instead of having to allocate the FIFO dynamically.
In addition:

- When writing into the FIFO and it's full return ENOSPC instead of
  ENOMEM thus making it easier to tell between "FIFO full" and
  "Dynamic memory allocation failed" when the error is propagated to
  a higher level.
  Also add an error message.

- When reading from the FIFO check whether it's empty.
  This is not strictly needed here but kfifo_out is annotated
  "must check" anyway.

Successfully tested it with the nuvoton-cir driver.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2016-01-25 12:38:09 -02:00
Heiner Kallweit
c1500ba0b6 [media] media: rc: remove unneeded code
Now that that the decoder modules are loaded on-demand we can move
loading the lirc module to rc_register_device directly and remove
unneeded functions and comments.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
2015-12-03 15:01:11 -02:00
Heiner Kallweit
d80ca8bd71 [media] media: rc: move check whether a protocol is enabled to the core
Checking whether a protocol is enabled and calling the related decoder
functions should be done by the rc core, not the protocol handlers.

Properly handle lirc considering that no protocol bit is set for lirc.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2015-11-19 11:39:17 -02:00
Heiner Kallweit
acc1c3c688 [media] media: rc: load decoder modules on-demand
Remove code for unconditional decoder module loading (except lirc).

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2015-11-19 11:38:41 -02:00
Heiner Kallweit
93cffffc18 [media] media: rc: fix decoder module unloading
Currently, if a decoder module is unloadad, the respective protocol
is still shown as enabled (if it was enabled before).
Fix this by resetting the respective protocol bits if a decoder
module is unloaded.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2015-11-19 11:36:29 -02:00
Linus Torvalds
9cfcc658da media updates for v4.3-rc1
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Merge tag 'media/v4.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media

Pull media updates from Mauro Carvalho Chehab:
 - new DVB frontend drivers: ascot2e, cxd2841er, horus3a, lnbh25
 - new HDMI capture driver: tc358743
 - new driver for NetUP DVB new boards (netup_unidvb)
 - IR support for DVBSky cards (smipcie-ir)
 - Coda driver has gain macroblock tiling support
 - Renesas R-Car gains JPEG codec driver
 - new DVB platform driver for STi boards: c8sectpfe
 - added documentation for the media core kABI to device-drivers DocBook
 - lots of driver fixups, cleanups and improvements

* tag 'media/v4.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (297 commits)
  [media] c8sectpfe: Remove select on undefined LIBELF_32
  [media] i2c: fix platform_no_drv_owner.cocci warnings
  [media] cx231xx: Use wake_up_interruptible() instead of wake_up_interruptible_nr()
  [media] tc358743: only queue subdev notifications if devnode is set
  [media] tc358743: add missing Kconfig dependency/select
  [media] c8sectpfe: Use %pad to print 'dma_addr_t'
  [media] DocBook media: Fix typo "the the" in xml files
  [media] tc358743: make reset gpio optional
  [media] tc358743: set direction of reset gpio using devm_gpiod_get
  [media] dvbdev: document most of the functions/data structs
  [media] dvb_frontend.h: document the struct dvb_frontend
  [media] dvb-frontend.h: document struct dtv_frontend_properties
  [media] dvb-frontend.h: document struct dvb_frontend_ops
  [media] dvb: Use DVBFE_ALGO_HW where applicable
  [media] dvb_frontend.h: document struct analog_demod_ops
  [media] dvb_frontend.h: Document struct dvb_tuner_ops
  [media] Docbook: Document struct analog_parameters
  [media] dvb_frontend.h: get rid of dvbfe_modcod
  [media] add documentation for struct dvb_tuner_info
  [media] dvb_frontend: document dvb_frontend_tune_settings
  ...
2015-09-05 18:21:14 -07:00
David Härdeman
72c5b7b24f Revert "[media] rc: rc-ir-raw: Add scancode encoder callback"
This reverts commit 9869da5bac.

The current code is not mature enough, the API should allow a single
protocol to be specified. Also, the current code contains heuristics
that will depend on module load order.

Signed-off-by: David Härdeman <david@hardeman.nu>
Acked-by: Antti Seppälä <a.seppala@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2015-08-19 07:04:49 -03:00
David Härdeman
86f216640e Revert "[media] rc: rc-ir-raw: Add Manchester encoder (phase encoder) helper"
This reverts commit 1d971d927e.

The current code is not mature enough, the API should allow a single
protocol to be specified. Also, the current code contains heuristics
that will depend on module load order.

Signed-off-by: David Härdeman <david@hardeman.nu>
Acked-by: Antti Seppälä <a.seppala@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2015-08-19 07:03:15 -03:00
David Härdeman
3a03b86fdc Revert "[media] rc: rc-core: Add support for encode_wakeup drivers"
This reverts commit 0d830b2d12.

The current code is not mature enough, the API should allow a single
protocol to be specified. Also, the current code contains heuristics
that will depend on module load order.

Signed-off-by: David Härdeman <david@hardeman.nu>
Acked-by: Antti Seppälä <a.seppala@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2015-08-19 07:03:00 -03:00
David Härdeman
fcb1309786 [media] rc-core: use an IDA rather than a bitmap
This patch changes rc-core to use the kernel facilities that are already
available for handling unique numbers instead of rolling its own bitmap
stuff.

Signed-off-by: David Härdeman <david@hardeman.nu>
Tested-by: Stefan Lippers-Hollmann <s.l-h@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2015-07-06 08:26:15 -03:00
James Hogan
0d830b2d12 [media] rc: rc-core: Add support for encode_wakeup drivers
Add support in rc-core for drivers which implement the wakeup scancode
filter by encoding the scancode using the raw IR encoders. This is by
way of rc_dev::encode_wakeup which should be set to true to make the
allowed wakeup protocols the same as the set of raw IR encoders.

As well as updating the sysfs interface to know which wakeup protocols
are allowed for encode_wakeup drivers, also ensure that the IR
decoders/encoders are loaded when an encode_wakeup driver is registered.

Signed-off-by: James Hogan <james@albanarts.com>
Signed-off-by: Antti Seppälä <a.seppala@gmail.com>
Cc: David Härdeman <david@hardeman.nu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2015-05-14 14:34:53 -03:00
Antti Seppälä
1d971d927e [media] rc: rc-ir-raw: Add Manchester encoder (phase encoder) helper
Adding a simple Manchester encoder to rc-core.
Manchester coding is used by at least RC-5 and RC-6 protocols and their
variants.

Signed-off-by: Antti Seppälä <a.seppala@gmail.com>
Signed-off-by: James Hogan <james@albanarts.com>
Cc: David Härdeman <david@hardeman.nu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2015-05-14 14:29:14 -03:00
James Hogan
9869da5bac [media] rc: rc-ir-raw: Add scancode encoder callback
Add a callback to raw ir handlers for encoding and modulating a scancode
to a set of raw events. This could be used for transmit, or for
converting a wakeup scancode filter to a form that is more suitable for
raw hardware wake up filters.

Signed-off-by: James Hogan <james@albanarts.com>
Signed-off-by: Antti Seppälä <a.seppala@gmail.com>
Cc: David Härdeman <david@hardeman.nu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2015-05-14 14:17:03 -03:00
Tomas Melin
14edb59333 [media] rc-core: fix protocol_change regression in ir_raw_event_register
IR receiver using nuvoton-cir and lirc required additional configuration
steps after upgrade from kernel 3.16 to 3.17-rcX. Bisected regression to
commit da6e162d6a ("[media] rc-core:
simplify sysfs code").

The regression comes from adding function change_protocol in ir-raw.c.
It changes behaviour so that only the protocol enabled by driver's
map_name will be active after registration. This breaks user space
behaviour, lirc does not get key press signals anymore.

Enable lirc protocol by default for ir raw decoders to restore original
behaviour.

Cc: stable@vger.kernel.org # for v3.17
Signed-off-by: Tomas Melin <tomas.melin@iki.fi>
Acked-by: David Härdeman <david@hardeman.nu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2014-10-30 09:09:28 -02:00
Marcel J.E. Mol
1dee9b59d6 [media] rc: Add support for decoding XMP protocol
This protocol is found on Dreambox remotes

[m.chehab@samsung.com: CodingStyle fixes and conflict fix]
Signed-off-by: Marcel Mol <marcel@mesa.nl>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2014-07-26 19:38:04 -03:00
David Härdeman
4924a311a6 [media] rc-core: rename ir-raw.c
Better to be coherent and prefix this file with rc-, in order to
help to identify to what subsystem it belongs.

This is in preparaton for a latter patch that will transform the
raw handling into a separate module.

Signed-off-by: David Härdeman <david@hardeman.nu>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2014-07-25 20:01:25 -03:00
Renamed from drivers/media/rc/ir-raw.c (Browse further)