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media: cec: check for non-OK/NACK conditions while claiming a LA 

During the configuration phase of a CEC adapter it is trying to claim a
free logical address by polling.

However, the code doesn't check if there were errors other than OK or NACK,
those are just treated as if the poll was NACKed.

Instead check for such errors and retry the poll. And if the problem persists
then don't claim this LA since there is something weird going on.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
This commit is contained in:
Hans Verkuil 2018-10-10 07:12:15 -04:00 committed by Mauro Carvalho Chehab
parent 7cf7b2e977
commit 55623b4169
1 changed files with 37 additions and 10 deletions
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47
drivers/media/cec/cec-adap.c
View File

@ -1180,6 +1180,8 @@ static int cec_config_log_addr(struct cec_adapter *adap,
{
struct cec_log_addrs *las = &adap->log_addrs;
struct cec_msg msg = { };
const unsigned int max_retries = 2;
unsigned int i;
int err;
if (cec_has_log_addr(adap, log_addr))
@ -1188,19 +1190,44 @@ static int cec_config_log_addr(struct cec_adapter *adap,
/* Send poll message */
msg.len = 1;
msg.msg[0] = (log_addr << 4) | log_addr;
err = cec_transmit_msg_fh(adap, &msg, NULL, true);
for (i = 0; i < max_retries; i++) {
err = cec_transmit_msg_fh(adap, &msg, NULL, true);
/*
* While trying to poll the physical address was reset
* and the adapter was unconfigured, so bail out.
*/
if (!adap->is_configuring)
return -EINTR;
if (err)
return err;
/*
* The message was aborted due to a disconnect or
* unconfigure, just bail out.
*/
if (msg.tx_status & CEC_TX_STATUS_ABORTED)
return -EINTR;
if (msg.tx_status & CEC_TX_STATUS_OK)
return 0;
if (msg.tx_status & CEC_TX_STATUS_NACK)
break;
/*
* Retry up to max_retries times if the message was neither
* OKed or NACKed. This can happen due to e.g. a Lost
* Arbitration condition.
*/
}
/*
* While trying to poll the physical address was reset
* and the adapter was unconfigured, so bail out.
* If we are unable to get an OK or a NACK after max_retries attempts
* (and note that each attempt already consists of four polls), then
* then we assume that something is really weird and that it is not a
* good idea to try and claim this logical address.
*/
if (!adap->is_configuring)
return -EINTR;
if (err)
return err;
if (msg.tx_status & CEC_TX_STATUS_OK)
if (i == max_retries)
return 0;
/*