On Sun, 23 Jul 2023 03:01:42 +0300
Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx> wrote:
> Panfrost IRQ handler may stuck for a long time, for example this happens
> when there is a bad HDMI connection and HDMI handler takes a long time to
> finish processing, holding Panfrost. Make Panfrost's job timeout handler
> to sync IRQ before checking fence signal status in order to prevent
> spurious job timeouts due to a slow IRQ processing.
>
> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>
> ---
>
> Changelog:
>
> v2: - Moved synchronize_irq() after first signal-check to avoid unnecessary
> blocking on syncing.
>
> - Added warn message about high interrupt latency.
>
> drivers/gpu/drm/panfrost/panfrost_job.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
> index dbc597ab46fb..a7663d7847a2 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_job.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_job.c
> @@ -720,6 +720,13 @@ static enum drm_gpu_sched_stat panfrost_job_timedout(struct drm_sched_job
> if (dma_fence_is_signaled(job->done_fence))
> return DRM_GPU_SCHED_STAT_NOMINAL;
>
> + synchronize_irq(pfdev->js->irq);
Can we add a comment here explaining why we're doing that?
> +
> + if (dma_fence_is_signaled(job->done_fence)) {
> + dev_warn(pfdev->dev, "unexpectedly high interrupt latency\n");
> + return DRM_GPU_SCHED_STAT_NOMINAL;
> + }
> +
> dev_err(pfdev->dev, "gpu sched timeout, js=%d, config=0x%x, status=0x%x, head=0x%x, tail=0x%x, sched_job=%p",
> js,
> job_read(pfdev, JS_CONFIG(js)),
