The img_ir_register_decoder() and img_ir_unregister_decoder() functions
were dropped prior to the img-ir driver being applied to simplify the
protocol decoder setup. However the declarations of these functions in
img-ir-hw.h were still included. Delete them since they're completely
unused.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
The end timer is used for switching back from repeat code timings when
no repeat codes have been received for a certain amount of time. When
the protocol is changed, the end timer is deleted synchronously with
del_timer_sync(), however this takes place while holding the main spin
lock, and the timer handler also needs to acquire the spin lock.
This opens the possibility of a deadlock on an SMP system if the
protocol is changed just as the repeat timer is expiring. One CPU could
end up in img_ir_set_decoder() holding the lock and waiting for the end
timer to complete, while the other CPU is stuck in the timer handler
spinning on the lock held by the first CPU.
Lockdep also spots a possible lock inversion in the same code, since
img_ir_set_decoder() acquires the img-ir lock before the timer lock, but
the timer handler will try and acquire them the other way around:
=========================================================
[ INFO: possible irq lock inversion dependency detected ]
3.18.0-rc5+ #957 Not tainted
---------------------------------------------------------
swapper/0/0 just changed the state of lock:
(((&hw->end_timer))){+.-...}, at: [<4006ae5c>] _call_timer_fn+0x0/0xfc
but this lock was taken by another, HARDIRQ-safe lock in the past:
(&(&priv->lock)->rlock#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(((&hw->end_timer)));
local_irq_disable();
lock(&(&priv->lock)->rlock#2);
lock(((&hw->end_timer)));
<Interrupt>
lock(&(&priv->lock)->rlock#2);
*** DEADLOCK ***
This is fixed by releasing the main spin lock while performing the
del_timer_sync() call. The timer is prevented from restarting before the
lock is reacquired by a new "stopping" flag which img_ir_handle_data()
checks before updating the timer.
---------------------------------------------------------
swapper/0/0 just changed the state of lock:
(((&hw->end_timer))){+.-...}, at: [<4006ae5c>] _call_timer_fn+0x0/0xfc
but this lock was taken by another, HARDIRQ-safe lock in the past:
(&(&priv->lock)->rlock#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(((&hw->end_timer)));
local_irq_disable();
lock(&(&priv->lock)->rlock#2);
lock(((&hw->end_timer)));
<Interrupt>
lock(&(&priv->lock)->rlock#2);
*** DEADLOCK ***
This is fixed by releasing the main spin lock while performing the
del_timer_sync() call. The timer is prevented from restarting before the
lock is reacquired by a new "stopping" flag which img_ir_handle_data()
checks before updating the timer.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Sifan Naeem <sifan.naeem@imgtec.com>
Cc: <stable@vger.kernel.org> # v3.15+
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
drivers/media/rc/img-ir/img-ir-nec.c:111:23: warning: symbol 'img_ir_nec' was not declared. Should it be static?
drivers/media/rc/img-ir/img-ir-jvc.c:54:23: warning: symbol 'img_ir_jvc' was not declared. Should it be static?
drivers/media/rc/img-ir/img-ir-sony.c:120:23: warning: symbol 'img_ir_sony' was not declared. Should it be static?
drivers/media/rc/img-ir/img-ir-sharp.c:75:23: warning: symbol 'img_ir_sharp' was not declared. Should it be static?
drivers/media/rc/img-ir/img-ir-sanyo.c:82:23: warning: symbol 'img_ir_sanyo' was not declared. Should it be static?
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Right now the protocol information is not preserved, rc-core gets handed a
scancode but has no idea which protocol it corresponds to.
This patch (which required reading through the source/keymap for all drivers,
not fun) makes the protocol information explicit which is important
documentation and makes it easier to e.g. support multiple protocols with one
decoder (think rc5 and rc-streamzap). The information isn't used yet so there
should be no functional changes.
[m.chehab@samsung.com: rebased, added cxusb and removed bad whitespacing]
Signed-off-by: David Härdeman <david@hardeman.nu>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Add the basic GPLv2+ license notice to the copyright headers at the top
of all the source files in the img-ir driver.
Reported-by: David Härdeman <david@hardeman.nu>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Add remote control input driver for the ImgTec Infrared block hardware
decoder, which is set up with timings for a specific protocol and
supports mask/value filtering and wake events.
The hardware decoder timing values, raw data to scan code conversion
function and scan code filter to raw data filter conversion function
will be provided in separate files for each protocol which this part of
the driver can use. The new generic scan code filter interface is made
use of to reduce interrupts and control wake events.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
James Hogan