diff options
| author | Hans Verkuil <hverkuil-cisco@xs4all.nl> | 2021-04-23 11:00:49 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-07-14 17:53:11 +0300 |
| commit | bb8b5e98b5f509bd1636232ee28d64429a76df6b (patch) | |
| tree | 861b44ea7bfe7ea42c1c5a10a8e91d1b7d90da76 /drivers/media/pci/cobalt/cobalt-driver.c | |
| parent | 162b85d3cf25d45de3acb24c5a8849c539057991 (diff) | |
| download | linux-bb8b5e98b5f509bd1636232ee28d64429a76df6b.tar.xz | |
media: cobalt: fix race condition in setting HPD
[ Upstream commit 3d37ef41bed0854805ab9af22c422267510e1344 ]
The cobalt_s_bit_sysctrl reads the old register value over PCI,
then changes a bit and sets writes the new value to the register.
This is used among other things for setting the HPD output pin.
But if the HPD is changed for multiple inputs at the same time,
then this causes a race condition where a stale value is read.
Serialize this function with a mutex.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/media/pci/cobalt/cobalt-driver.c')
| -rw-r--r-- | drivers/media/pci/cobalt/cobalt-driver.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/media/pci/cobalt/cobalt-driver.c b/drivers/media/pci/cobalt/cobalt-driver.c index 0695078ef812..1bd8bbe57a30 100644 --- a/drivers/media/pci/cobalt/cobalt-driver.c +++ b/drivers/media/pci/cobalt/cobalt-driver.c @@ -667,6 +667,7 @@ static int cobalt_probe(struct pci_dev *pci_dev, return -ENOMEM; cobalt->pci_dev = pci_dev; cobalt->instance = i; + mutex_init(&cobalt->pci_lock); retval = v4l2_device_register(&pci_dev->dev, &cobalt->v4l2_dev); if (retval) { |