Hi Mauro,
Have you received my letter which is cited below?
I also tried to get in touch with you on #linuxtv.
On Thu, Aug 25, 2016 at 05:46:06PM +0300, Andrey Utkin wrote:
> For some reason (maybe "unlisted recipients"?), my reply didn't get
> through to maillists. Resending my reply.
>
> On Wed, Aug 24, 2016, at 19:30, Mauro Carvalho Chehab wrote:
> > As warned by smatch:
> > drivers/media/pci/tw5864/tw5864-core.c:160 tw5864_h264_isr() error: double lock 'irqsave:flags'
> > drivers/media/pci/tw5864/tw5864-core.c:174 tw5864_h264_isr() error: double unlock 'irqsave:flags'
> >
> > Remove the IRQ duplicated lock.
> >
> > Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
> > ---
> > drivers/media/pci/tw5864/tw5864-core.c | 2 --
> > 1 file changed, 2 deletions(-)
> >
> > diff --git a/drivers/media/pci/tw5864/tw5864-core.c
> > b/drivers/media/pci/tw5864/tw5864-core.c
> > index 440cd7bb8d04..e3d884e963c0 100644
> > --- a/drivers/media/pci/tw5864/tw5864-core.c
> > +++ b/drivers/media/pci/tw5864/tw5864-core.c
> > @@ -157,12 +157,10 @@ static void tw5864_h264_isr(struct tw5864_dev *dev)
> >
> > cur_frame = next_frame;
> >
> > - spin_lock_irqsave(&input->slock, flags);
> > input->frame_seqno++;
> > input->frame_gop_seqno++;
> > if (input->frame_gop_seqno >= input->gop)
> > input->frame_gop_seqno = 0;
> > - spin_unlock_irqrestore(&input->slock, flags);
> > } else {
> > dev_err(&dev->pci->dev,
> > "Skipped frame on input %d because all buffers busy\n",
>
>
> Thank you very much for catching this issue, but NACK on the patch.
>
> These two lock operations are on different spinlocks. One for device,
> another
> one for input (a subordinate entity of device). What is superfluous here
> is
> second _irqsave. Also "flags" variable reuse is wrong. So what would be
> right,
> in my opinion, is the following (going to submit this patch):
>
> diff --git a/drivers/media/pci/tw5864/tw5864-core.c
> b/drivers/media/pci/tw5864/tw5864-core.c
> index 440cd7b..1d43b96 100644
> --- a/drivers/media/pci/tw5864/tw5864-core.c
> +++ b/drivers/media/pci/tw5864/tw5864-core.c
> @@ -157,12 +157,12 @@ static void tw5864_h264_isr(struct tw5864_dev
> *dev)
>
> cur_frame = next_frame;
>
> - spin_lock_irqsave(&input->slock, flags);
> + spin_lock(&input->slock);
> input->frame_seqno++;
> input->frame_gop_seqno++;
> if (input->frame_gop_seqno >= input->gop)
> input->frame_gop_seqno = 0;
> - spin_unlock_irqrestore(&input->slock, flags);
> + spin_unlock(&input->slock);
> } else {
> dev_err(&dev->pci->dev,
> "Skipped frame on input %d because all buffers
> busy\n",
> --
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