linux.git/drivers/media/cec, branch v5.19

media: cec-adap.c: drop activate_cnt, use state info instead

2022-05-13T09:29:39+00:00

Using an activation counter to decide when the enable or disable the
cec adapter is not the best approach and can lead to race conditions.

Change this to determining the current status of the adapter, and
enable or disable the adapter accordingly.

It now only needs to be called whenever there is a chance that the
state changes, and it can handle enabling/disabling monitoring as
well if needed.

This simplifies the code and it should be a more robust approach as well.

Signed-off-by: Hans Verkuil 
Signed-off-by: Mauro Carvalho Chehab

media: cec-adap.c: reconfigure if the PA changes during configuration

2022-05-13T09:29:16+00:00

If the physical address changes (i.e. becomes invalid, then valid again)
while the adapter is still claiming free logical addresses, then trigger
a reconfiguration since any claimed LAs may now be stale.

Signed-off-by: Hans Verkuil 
Signed-off-by: Mauro Carvalho Chehab

media: cec-adap.c: fix is_configuring state

2022-05-13T09:28:54+00:00

If an adapter is trying to claim a free logical address then it is
in the 'is_configuring' state. If during that process the cable is
disconnected (HPD goes low, which in turn invalidates the physical
address), then cec_adap_unconfigure() is called, and that set the
is_configuring boolean to false, even though the thread that's
trying to claim an LA is still running.

Don't touch the is_configuring bool in cec_adap_unconfigure(), it
will eventually be cleared by the thread. By making that change
the cec_config_log_addr() function also had to change: it was
aborting if is_configuring became false (since that is what
cec_adap_unconfigure() did), but that no longer works. Instead
check if the physical address is invalid. That is a much
more appropriate check anyway.

This fixes a bug where the the adapter could be disabled even
though the device was still configuring. This could cause POLL
transmits to time out.

Signed-off-by: Hans Verkuil 
Signed-off-by: Mauro Carvalho Chehab

media: cec-adap.c: stop trying LAs on CEC_TX_STATUS_TIMEOUT

2022-05-13T09:28:35+00:00

If, while trying to claim a free logical address, a POLL message
times out, then abort this process. A CEC_TX_STATUS_TIMEOUT
should be handled the same as a CEC_TX_STATUS_ABORTED.

This avoids a situation where transmits time out due to a
driver or hardware bug and it takes ages before the attempt
to find available free logical addresses finishes.

Signed-off-by: Hans Verkuil 
Signed-off-by: Mauro Carvalho Chehab

media: cec-adap.c: don't unconfigure if already unconfigured

2022-05-13T09:28:06+00:00

The __cec_s_log_addrs() function can configure or unconfigure the
adapter. The ioctl handler in cec-api.c will prevent it from being
called to configure the adapter if it was already configured (or in
the process of configuring). But it can still be called to unconfigure
an already unconfigured adapter, and it didn't check for that.

This can cause cec_activate_cnt_dec() to be called too often, causing
a WARN_ON.

Instead first check if adap->log_addrs.num_log_addrs == 0 and return
since in that case the adapter is already unconfigured.

Signed-off-by: Hans Verkuil 
Signed-off-by: Mauro Carvalho Chehab

media: cec-pin.c: don't zero work_pin_num_events in adap_enable

2022-05-13T09:27:47+00:00

It's OK to keep the pending pin events when disabling or
enabling the 'adapter'. Zeroing this can cause a race condition
if this happens when the pin kthread is handling a pin event
and calls atomic_dec later, causing work_pin_num_events to become
negative.

Just leave pending events in the queue, they'll be read eventually.

Signed-off-by: Hans Verkuil 
Signed-off-by: Mauro Carvalho Chehab

media: cec-pin.c: disabling the adapter cannot call kthread_stop

2022-05-13T09:27:19+00:00

When the adap_enable callback is called the adap->lock is held.
When disabling the adapter it attempts to stop the kthread that
deals with receiving and transmitting messages. However, kthread_stop
waits for the thread to stop, so all that time adap->lock is held.

Unfortunately, the kernel thread itself can call functions that take
that same lock, so a deadlock can occur.

Change the logic to keep the kernel thread running and instead when
disabling the adapter, just set the pin to high, go to idle and then
to state OFF and disable the interrupt. Only stop the kernel thread
when the adapter is deleted.

This way disabling the adapter will not wait for anything and the
deadlock is avoided.

Signed-off-by: Hans Verkuil 
Signed-off-by: Mauro Carvalho Chehab

media: cec: seco: remove byte handling from smb_word_op

2022-05-13T09:02:17+00:00

smb_word_op() has a parameter data_format that
determines if the data is either a byte or
word.  From inspection, smb_word_op() is only
used by the macros smb_wr16() and smb_rd16()
both pass in CMD_WORD_DATA. There is no use of
smb_word_op() that passes in CMD_BYTE_DATA.
So remove the byte handling.

Signed-off-by: Tom Rix 
Signed-off-by: Hans Verkuil 
Signed-off-by: Mauro Carvalho Chehab

media: cec: add optional adap_configured callback

2022-04-24T06:41:35+00:00

This new optional callback is called when the adapter is fully configured
or fully unconfigured. Some drivers may have to take action when this
happens.

Signed-off-by: Hans Verkuil 
Signed-off-by: Mauro Carvalho Chehab

media: cec: add xfer_timeout_ms field

2022-04-24T06:41:06+00:00

Allow drivers to change the transmit timeout value, i.e. after how
long should a transmit be considered 'lost', i.e. the corresponding
cec_transmit_done_ts was never called.

Some CEC devices have their own timeout, and so this timeout value must be
longer than that hardware timeout value. If it is shorter then the
framework would consider the transmit lost, even though it is effectively
still in progress at the hardware level.

Signed-off-by: Hans Verkuil 
Signed-off-by: Mauro Carvalho Chehab