From 3f98da9636029486b86eb63f0b57b91dcbd880b0 Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Mon, 21 Nov 2016 13:15:45 -0200 Subject: [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: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/cec/cec-adap.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'drivers/media/cec') diff --git a/drivers/media/cec/cec-adap.c b/drivers/media/cec/cec-adap.c index d9c6f2c..0ea4efb 100644 --- a/drivers/media/cec/cec-adap.c +++ b/drivers/media/cec/cec-adap.c @@ -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; -- cgit v1.1