[PATCH 4.9 085/109] [media] cec: initiator should be the same as the destination for, poll

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Hans Verkuil <hverkuil@xxxxxxxxx>


[ Upstream commit 42980da2eb7eb9695d8efc0c0ef145cbbb993b2c ]

Poll messages that are used to allocate a logical address should
use the same initiator as the destination. Instead, it expected that
the initiator was 0xf which is not according to the standard.

This also had consequences for the message checks in cec_transmit_msg_fh
that incorrectly rejected poll messages with the same initiator and
destination.

Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/staging/media/cec/cec-adap.c |    7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

--- a/drivers/staging/media/cec/cec-adap.c
+++ b/drivers/staging/media/cec/cec-adap.c
@@ -608,8 +608,7 @@ int cec_transmit_msg_fh(struct cec_adapt
 	}
 	memset(msg->msg + msg->len, 0, sizeof(msg->msg) - msg->len);
 	if (msg->len == 1) {
-		if (cec_msg_initiator(msg) != 0xf ||
-		    cec_msg_destination(msg) == 0xf) {
+		if (cec_msg_destination(msg) == 0xf) {
 			dprintk(1, "cec_transmit_msg: invalid poll message\n");
 			return -EINVAL;
 		}
@@ -634,7 +633,7 @@ int cec_transmit_msg_fh(struct cec_adapt
 		dprintk(1, "cec_transmit_msg: destination is the adapter itself\n");
 		return -EINVAL;
 	}
-	if (cec_msg_initiator(msg) != 0xf &&
+	if (msg->len > 1 && adap->is_configured &&
 	    !cec_has_log_addr(adap, cec_msg_initiator(msg))) {
 		dprintk(1, "cec_transmit_msg: initiator has unknown logical address %d\n",
 			cec_msg_initiator(msg));
@@ -883,7 +882,7 @@ static int cec_config_log_addr(struct ce
 
 	/* Send poll message */
 	msg.len = 1;
-	msg.msg[0] = 0xf0 | log_addr;
+	msg.msg[0] = (log_addr << 4) | log_addr;
 	err = cec_transmit_msg_fh(adap, &msg, NULL, true);
 
 	/*