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Commit e509ffb5 authored by Hans Verkuil's avatar Hans Verkuil Committed by Ray Zhang
Browse files

[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.

Change-Id: I5f5f361ef9135445382764659280583fa1cbe10c
Signed-off-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
Git-commit: 3f98da9636029486b86eb63f0b57b91dcbd880b0
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git


Signed-off-by: default avatarRay Zhang <rayz@codeaurora.org>
parent 0f9cbbd5

drivers/media/cec/cec-adap.c

+15 −0
Original line number Diff line number Diff line
@@ -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;