[PATCH 5.18 167/879] media: cec-adap.c: fix is_configuring state

Greg Kroah-Hartman
2022-06-07T22:17:25Z

From: Hans Verkuil <hverkuil-cisco@xs4all.nl>

[ Upstream commit 59267fc34f4900dcd2ec3295f6be04b79aee2186 ]

If an adapter is trying to claim a free logical address then it is
in the 'is_configuring' state. If during that process the cable is
disconnected (HPD goes low, which in turn invalidates the physical
address), then cec_adap_unconfigure() is called, and that set the
is_configuring boolean to false, even though the thread that's
trying to claim an LA is still running.

Don't touch the is_configuring bool in cec_adap_unconfigure(), it
will eventually be cleared by the thread. By making that change
the cec_config_log_addr() function also had to change: it was
aborting if is_configuring became false (since that is what
cec_adap_unconfigure() did), but that no longer works. Instead
check if the physical address is invalid. That is a much
more appropriate check anyway.

This fixes a bug where the the adapter could be disabled even
though the device was still configuring. This could cause POLL
transmits to time out.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/media/cec/core/cec-adap.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/media/cec/core/cec-adap.c b/drivers/media/cec/core/cec-adap.c
index 2e12331c12a9..01766e744772 100644
--- a/drivers/media/cec/core/cec-adap.c
+++ b/drivers/media/cec/core/cec-adap.c
@@ -1278,7 +1278,7 @@ static int cec_config_log_addr(struct cec_adapter *adap,
* While trying to poll the physical address was reset
* and the adapter was unconfigured, so bail out.
*/
- if (!adap->is_configuring)
+ if (adap->phys_addr == CEC_PHYS_ADDR_INVALID)
return -EINTR;

if (err)
@@ -1335,7 +1335,6 @@ static void cec_adap_unconfigure(struct cec_adapter *adap)
adap->phys_addr != CEC_PHYS_ADDR_INVALID)
WARN_ON(adap->ops->adap_log_addr(adap, CEC_LOG_ADDR_INVALID));
adap->log_addrs.log_addr_mask = 0;
- adap->is_configuring = false;
adap->is_configured = false;
cec_flush(adap);
wake_up_interruptible(&adap->kthread_waitq);
@@ -1527,9 +1526,10 @@ static int cec_config_thread_func(void *arg)
for (i = 0; i < las->num_log_addrs; i++)
las->log_addr[i] = CEC_LOG_ADDR_INVALID;
cec_adap_unconfigure(adap);
+ adap->is_configuring = false;
adap->kthread_config = NULL;
- mutex_unlock(&adap->lock);
complete(&adap->config_completion);
+ mutex_unlock(&adap->lock);
return 0;
}

--
2.35.1