Re: [PATCH v1 4/8] drm/panthor: Fix the full_tick check

[Steven Price <steven.price@arm.com>]

On 06/11/2025 14:46, Boris Brezillon wrote:
> We have a full tick when the remaining time to the next tick is zero,
> not the other way around. Declare a full_tick variable so we don't get
> that test wrong in other places.
> 
> Fixes: de8548813824 ("drm/panthor: Add the scheduler logical block")
> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>

Reviewed-by: Steven Price <steven.price@arm.com>

> ---
>  drivers/gpu/drm/panthor/panthor_sched.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c
> index 69cc1b4c23f2..b6489e9ba1f0 100644
> --- a/drivers/gpu/drm/panthor/panthor_sched.c
> +++ b/drivers/gpu/drm/panthor/panthor_sched.c
> @@ -2349,6 +2349,7 @@ static void tick_work(struct work_struct *work)
>  	u64 remaining_jiffies = 0, resched_delay;
>  	u64 now = get_jiffies_64();
>  	int prio, ret, cookie;
> +	bool full_tick;
>  
>  	if (!drm_dev_enter(&ptdev->base, &cookie))
>  		return;
> @@ -2360,15 +2361,17 @@ static void tick_work(struct work_struct *work)
>  	if (time_before64(now, sched->resched_target))
>  		remaining_jiffies = sched->resched_target - now;
>  
> +	full_tick = remaining_jiffies == 0;
> +
>  	mutex_lock(&sched->lock);
>  	if (panthor_device_reset_is_pending(sched->ptdev))
>  		goto out_unlock;
>  
> -	tick_ctx_init(sched, &ctx, remaining_jiffies != 0);
> +	tick_ctx_init(sched, &ctx, full_tick);
>  	if (ctx.csg_upd_failed_mask)
>  		goto out_cleanup_ctx;
>  
> -	if (remaining_jiffies) {
> +	if (!full_tick) {
>  		/* Scheduling forced in the middle of a tick. Only RT groups
>  		 * can preempt non-RT ones. Currently running RT groups can't be
>  		 * preempted.