mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-08-23 01:10:04 +00:00
Code Issues Releases Wiki Activity

[media] cec: ignore messages that we initiated

Browse source 
Some CEC adapters will receive messages that they initiated. Add a
check that will ignore such messages.

Most hardware behaves correctly in this respect, but I have seen
adapters that don't, so just filter this out in the framework.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
This commit is contained in:
Hans Verkuil 2016-11-21 13:15:45 -02:00 committed by Mauro Carvalho Chehab
parent 7febb418a3
commit 3f98da9636
1 changed files with 15 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

15
drivers/media/cec/cec-adap.c
View file

@ -869,6 +869,21 @@ void cec_received_msg(struct cec_adapter *adap, struct cec_msg *msg)
if (WARN_ON(!msg->len || msg->len > CEC_MAX_MSG_SIZE))
return;
/*
* Some CEC adapters will receive the messages that they transmitted.
* This test filters out those messages by checking if we are the
* initiator, and just returning in that case.
*
* Note that this won't work if this is an Unregistered device.
*
* It is bad practice if the hardware receives the message that it
* transmitted and luckily most CEC adapters behave correctly in this
* respect.
*/
if (msg_init != CEC_LOG_ADDR_UNREGISTERED &&
cec_has_log_addr(adap, msg_init))
return;
msg->rx_ts = ktime_get_ns();
msg->rx_status = CEC_RX_STATUS_OK;
msg->sequence = msg->reply = msg->timeout = 0;