Re: [PATCH v2] drm/imagination: Update the trace point pvr_job_submit_fw()

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The `pvr_job_submit_fw` tracepoint for fragment jobs in paired submissions is emitted asynchronously from actual firmware submission, breaking the tracepoint's intended semantics.
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--- Patch [1]: [PATCH v2] drm/imagination: Update the trace point pvr_job_submit_fw() ---
commit f1ff23a928ba06505b47c3b88a51019e853a537e
Author: Brajesh Gupta <brajesh.gupta@imgtec.com>
drm/imagination: Update the trace point pvr_job_submit_fw()

This patch moves the trace recording for pvr_job_submit_fw() to occur after
writing the command to the Kernel circular buffer. The intention is to more
accurately represent the exact moment a command is submitted to the firmware.

> diff --git a/drivers/gpu/drm/imagination/pvr_queue.c b/drivers/gpu/drm/imagination/pvr_queue.c
> index 941c017399fc3..fd968d7def660 100644
> --- a/drivers/gpu/drm/imagination/pvr_queue.c
> +++ b/drivers/gpu/drm/imagination/pvr_queue.c
[ ... ]
> @@ -758,6 +756,7 @@ static struct dma_fence *pvr_queue_run_job(struct drm_sched_job *sched_job)
>  	 */
>  	if (job->paired_job && job->type == DRM_PVR_JOB_TYPE_FRAGMENT &&
>  	    job->done_fence->ops) {
> +		trace_pvr_job_submit_fw(job);

[Severity: Medium]
For paired submissions, the geometry scheduler thread submits both the
geometry and fragment jobs to the firmware simultaneously in a combined kick.

Since this path executes in the independent fragment scheduler thread, doesn't
emitting the tracepoint here mean it happens asynchronously from the actual
firmware submission?

Because the fragment scheduler thread runs independently, it may wake up and
emit this tracepoint an arbitrary amount of time after the combined hardware
submission (or even after the hardware has finished the job).

Would it better represent the submission time to emit the fragment job's
tracepoint from the geometry job's pvr_queue_run_job() execution, where both
are actually submitted to the firmware via pvr_cccb_send_kccb_combined_kick()?

>  		return dma_fence_get(job->done_fence);
>  	}

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Sashiko AI review · https://sashiko.dev/#/patchset/20260724-b4-tracepoint-fix-v2-1-e6a81a348394@imgtec.com?part=1