Commit 3f98da96 authored by Hans Verkuil's avatar Hans Verkuil Committed by Mauro Carvalho Chehab

[media] cec: ignore messages that we initiated

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: default avatarHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent 7febb418
...@@ -869,6 +869,21 @@ void cec_received_msg(struct cec_adapter *adap, struct cec_msg *msg) ...@@ -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)) if (WARN_ON(!msg->len || msg->len > CEC_MAX_MSG_SIZE))
return; 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_ts = ktime_get_ns();
msg->rx_status = CEC_RX_STATUS_OK; msg->rx_status = CEC_RX_STATUS_OK;
msg->sequence = msg->reply = msg->timeout = 0; msg->sequence = msg->reply = msg->timeout = 0;
......
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