[PATCH] media: bcm2835-unicam: Fix log status runtime access

[Sakari Ailus]

Hi Eugen, Jean-Michel,

On Fri, May 22, 2026 at 10:31:51AM +0200, Jean-Michel Hautbois wrote:
> Hi Eugen,
> 
> Thanks for the fix, the issue is real, but I think the patch leaks a runtime
> PM reference.
> 
> Le 21/05/2026 à 20:09, Eugen Hristev a écrit :
> > When requesting log status, the block might be powered
> > off, but registers are being read.
> > Avoid reading the registers if the device is not
> > resumed, thus also avoid powering up the device just
> > for log status.

Please rewrap this, most editors can do that automatically.

> > 
> > Fixes: 392cd78d495f ("media: bcm2835-unicam: Add support for CCP2/CSI2 camera interface")
> > Signed-off-by: Eugen Hristev <ehristev at kernel.org>
> > ---
> >   drivers/media/platform/broadcom/bcm2835-unicam.c | 4 ++++
> >   1 file changed, 4 insertions(+)
> > 
> > diff --git a/drivers/media/platform/broadcom/bcm2835-unicam.c b/drivers/media/platform/broadcom/bcm2835-unicam.c
> > index 8d28ba0b59a3..818694f007e2 100644
> > --- a/drivers/media/platform/broadcom/bcm2835-unicam.c
> > +++ b/drivers/media/platform/broadcom/bcm2835-unicam.c
> > @@ -2052,6 +2052,10 @@ static int unicam_log_status(struct file *file, void *fh)
> >   		 node->fmt.fmt.pix.width, node->fmt.fmt.pix.height);
> >   	dev_info(unicam->dev, "V4L2 format:         %08x\n",
> >   		 node->fmt.fmt.pix.pixelformat);
> > +
> > +	if (!pm_runtime_get_if_in_use(unicam->dev))
> > +		return 0;
> > +
> 
> pm_runtime_get_if_in_use() returns 1 and increments the usage counter is
> active and in use.

Also, should this be pm_runtime_get_if_active() instead?

> 
> I think we need to add:
> pm_runtime_put(unicam->dev);
> 
> Just before the return 0;
> 
> BTW, we may miss a dev_info explaining why the live data is skipped when the
> device is suspended ?

-- 
Regards,

Sakari Ailus