2023-07-23 00:45:59

by Dmitry Osipenko

[permalink] [raw]
Subject: [PATCH v2] drm/panfrost: Sync IRQ by job's timeout handler

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 <[email protected]>
---

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);
+
+ 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)),
--
2.41.0



2023-07-24 08:15:11

by Boris Brezillon

[permalink] [raw]
Subject: Re: [PATCH v2] drm/panfrost: Sync IRQ by job's timeout handler

On Sun, 23 Jul 2023 03:01:42 +0300
Dmitry Osipenko <[email protected]> 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 <[email protected]>
> ---
>
> 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)),


2023-07-24 09:47:10

by Steven Price

[permalink] [raw]
Subject: Re: [PATCH v2] drm/panfrost: Sync IRQ by job's timeout handler

On 24/07/2023 07:57, Boris Brezillon wrote:
> On Sun, 23 Jul 2023 03:01:42 +0300
> Dmitry Osipenko <[email protected]> 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 <[email protected]>
>> ---
>>
>> 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?

Agreed, with a comment added:

Reviewed-by: Steven Price <[email protected]>

>> +
>> + 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)),
>


Subject: Re: [PATCH v2] drm/panfrost: Sync IRQ by job's timeout handler

Il 23/07/23 02:01, Dmitry Osipenko ha scritto:
> 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 <[email protected]>

Reviewed-by: AngeloGioacchino Del Regno <[email protected]>

Also, on MediaTek MT8192 and MT8195 Chromebooks:

Tested-by: AngeloGioacchino Del Regno <[email protected]>