On Wed, Aug 3, 2022 at 12:52 PM Akhil P Oommen <quic_akhilpo@xxxxxxxxxxx> wrote:
>
> On 8/3/2022 10:53 PM, Rob Clark wrote:
> > From: Rob Clark <robdclark@xxxxxxxxxxxx>
> >
> > Don't directly restart the hangcheck timer from the timer handler, but
> > instead start it after the recover_worker replays remaining jobs.
> >
> > If the kthread is blocked for other reasons, there is no point to
> > immediately restart the timer. Fixes a random symptom of the problem
> > fixed in the next patch.
> >
> > Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
> > ---
> > drivers/gpu/drm/msm/msm_gpu.c | 14 +++++++++-----
> > 1 file changed, 9 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
> > index fba85f894314..8f9c48eabf7d 100644
> > --- a/drivers/gpu/drm/msm/msm_gpu.c
> > +++ b/drivers/gpu/drm/msm/msm_gpu.c
> > @@ -328,6 +328,7 @@ find_submit(struct msm_ringbuffer *ring, uint32_t fence)
> > }
> >
> > static void retire_submits(struct msm_gpu *gpu);
> > +static void hangcheck_timer_reset(struct msm_gpu *gpu);
> >
> > static void get_comm_cmdline(struct msm_gem_submit *submit, char **comm, char **cmd)
> > {
> > @@ -420,6 +421,8 @@ static void recover_worker(struct kthread_work *work)
> > }
> >
> > if (msm_gpu_active(gpu)) {
> > + bool restart_hangcheck = false;
> > +
> > /* retire completed submits, plus the one that hung: */
> > retire_submits(gpu);
> >
> > @@ -436,10 +439,15 @@ static void recover_worker(struct kthread_work *work)
> > unsigned long flags;
> >
> > spin_lock_irqsave(&ring->submit_lock, flags);
> > - list_for_each_entry(submit, &ring->submits, node)
> > + list_for_each_entry(submit, &ring->submits, node) {
> > gpu->funcs->submit(gpu, submit);
> > + restart_hangcheck = true;
> > + }
> > spin_unlock_irqrestore(&ring->submit_lock, flags);
> > }
> > +
> > + if (restart_hangcheck)
> > + hangcheck_timer_reset(gpu);
> > }
> >
> > mutex_unlock(&gpu->lock);
> > @@ -515,10 +523,6 @@ static void hangcheck_handler(struct timer_list *t)
> > kthread_queue_work(gpu->worker, &gpu->recover_work);
> > }
> >
> > - /* if still more pending work, reset the hangcheck timer: */
> In the scenario mentioned here, shouldn't we restart the timer?
yeah, actually the case where we don't want to restart the timer is
*only* when we schedule recover_work..
BR,
-R
>
> -Akhil.
> > - if (fence_after(ring->fctx->last_fence, ring->hangcheck_fence))
> > - hangcheck_timer_reset(gpu);
> > -
> > /* workaround for missing irq: */
> > msm_gpu_retire(gpu);
> > }
> >
>
