On Thu, Nov 13, 2025 at 7:32 AM Boris Brezillon
<[email protected]> wrote:
>
> If the group is already assigned a slot but was idle before this job
> submission, we need to make sure the priority rotation happens in the
> future. Extract the existing logic living in group_schedule_locked()
> and call this new sched_resume_tick() helper from the "group is
> assigned a slot" path.
>
> v2:
> - Add R-b
>
> Fixes: de8548813824 ("drm/panthor: Add the scheduler logical block")
> Signed-off-by: Boris Brezillon <[email protected]>
> Reviewed-by: Steven Price <[email protected]>
> ---
> drivers/gpu/drm/panthor/panthor_sched.c | 43 +++++++++++++++++++------
> 1 file changed, 34 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/panthor/panthor_sched.c
> b/drivers/gpu/drm/panthor/panthor_sched.c
> index 0394f377c284..d1484f4a1c5b 100644
> --- a/drivers/gpu/drm/panthor/panthor_sched.c
> +++ b/drivers/gpu/drm/panthor/panthor_sched.c
> @@ -2543,14 +2543,33 @@ static void sync_upd_work(struct work_struct *work)
> sched_queue_delayed_work(sched, tick, 0);
> }
>
> +static void sched_resume_tick(struct panthor_device *ptdev)
> +{
> + struct panthor_scheduler *sched = ptdev->scheduler;
> + u64 delay_jiffies, now;
> +
> + drm_WARN_ON(&ptdev->base, sched->resched_target != U64_MAX);
> +
> + /* Scheduler tick was off, recalculate the resched_target based on the
> + * last tick event, and queue the scheduler work.
> + */
> + now = get_jiffies_64();
> + sched->resched_target = sched->last_tick + sched->tick_period;
> + if (sched->used_csg_slot_count == sched->csg_slot_count &&
> + time_before64(now, sched->resched_target))
> + delay_jiffies = min_t(unsigned long, sched->resched_target -
> now, ULONG_MAX);
> + else
> + delay_jiffies = 0;
> +
> + sched_queue_delayed_work(sched, tick, delay_jiffies);
> +}
> +
> static void group_schedule_locked(struct panthor_group *group, u32
> queue_mask)
> {
> struct panthor_device *ptdev = group->ptdev;
> struct panthor_scheduler *sched = ptdev->scheduler;
> struct list_head *queue = &sched->groups.runnable[group->priority];
> - u64 delay_jiffies = 0;
> bool was_idle;
> - u64 now;
>
> if (!group_can_run(group))
> return;
> @@ -2595,13 +2614,7 @@ static void group_schedule_locked(struct panthor_group
> *group, u32 queue_mask)
> /* Scheduler tick was off, recalculate the resched_target based on the
> * last tick event, and queue the scheduler work.
> */
> - now = get_jiffies_64();
> - sched->resched_target = sched->last_tick + sched->tick_period;
> - if (sched->used_csg_slot_count == sched->csg_slot_count &&
> - time_before64(now, sched->resched_target))
> - delay_jiffies = min_t(unsigned long, sched->resched_target -
> now, ULONG_MAX);
> -
> - sched_queue_delayed_work(sched, tick, delay_jiffies);
> + sched_resume_tick(ptdev);
> }
>
> static void queue_stop(struct panthor_queue *queue,
> @@ -3202,6 +3215,18 @@ queue_run_job(struct drm_sched_job *sched_job)
>
> group_schedule_locked(group, BIT(job->queue_idx));
> } else {
> + u32 queue_mask = BIT(job->queue_idx);
> + bool resume_tick = group_is_idle(group) &&
> + (group->idle_queues & queue_mask) &&
> + !(group->blocked_queues & queue_mask) &&
> + sched->resched_target == U64_MAX;
The logic here should be the same as the first part of
group_schedule_locked. I wonder if we can refactor that as well.
> +
> + /* We just added something to the queue, so it's no longer
> idle. */
> + group->idle_queues &= ~BIT(job->queue_idx);
group->idle_queues &= queue_mask;
> +
> + if (resume_tick)
> + sched_resume_tick(ptdev);
> +
> gpu_write(ptdev, CSF_DOORBELL(queue->doorbell_id), 1);
> if (!sched->pm.has_ref &&
> !(group->blocked_queues & BIT(job->queue_idx))) {
> --
> 2.51.1
>
