Re: [PATCH v3 2/6] drm/panthor: Minor scheduler refactoring
From: Boris Brezillon
Date: Fri Sep 11 2026 - 10:32:51 EST
On Fri, 11 Sep 2026 13:40:10 +0200
Ketil Johnsen <ketil.johnsen@xxxxxxx> wrote:
> From: Florent Tomasin <florent.tomasin@xxxxxxx>
>
> Refactor parts of the group scheduling logic into new helper functions.
> This will simplify addition of the protected mode feature.
>
> Remove redundant assignments of csg_slot.
>
> Signed-off-by: Florent Tomasin <florent.tomasin@xxxxxxx>
> Co-developed-by: Ketil Johnsen <ketil.johnsen@xxxxxxx>
> Signed-off-by: Ketil Johnsen <ketil.johnsen@xxxxxxx>
Reviewed-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
>
> ---
>
> v3:
> - Use panthor_fw_csg_endpoint_req_update() (was rebase mistake)
> - Function rename to tick_ctx_update_group_prio()
>
> v2:
> - Moved option to ding only the CSG doorbell to later patch
> ---
> drivers/gpu/drm/panthor/panthor_sched.c | 131 ++++++++++++++----------
> 1 file changed, 79 insertions(+), 52 deletions(-)
>
> diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c
> index 60b2417deb81b..1123cf36a7bca 100644
> --- a/drivers/gpu/drm/panthor/panthor_sched.c
> +++ b/drivers/gpu/drm/panthor/panthor_sched.c
> @@ -2344,12 +2344,81 @@ tick_ctx_cleanup(struct panthor_scheduler *sched,
> }
> }
>
> +static void
> +tick_ctx_evict_group(struct panthor_scheduler *sched,
> + struct panthor_csg_slots_upd_ctx *upd_ctx,
> + struct panthor_group *group)
> +{
> + struct panthor_device *ptdev = sched->ptdev;
> +
> + if (drm_WARN_ON(&ptdev->base, group->csg_id < 0))
> + return;
> +
> + csgs_upd_ctx_queue_reqs(ptdev, upd_ctx, group->csg_id,
> + group_can_run(group) ?
> + CSG_STATE_SUSPEND : CSG_STATE_TERMINATE,
> + CSG_STATE_MASK);
> +}
> +
> +static void
> +tick_ctx_update_group_prio(struct panthor_scheduler *sched,
> + struct panthor_csg_slots_upd_ctx *upd_ctx,
> + struct panthor_group *group,
> + int new_csg_prio)
> +{
> + struct panthor_device *ptdev = sched->ptdev;
> + struct panthor_fw_csg_iface *csg_iface;
> + struct panthor_csg_slot *csg_slot;
> +
> + if (group->csg_id < 0)
> + return;
> +
> + csg_iface = panthor_fw_get_csg_iface(ptdev, group->csg_id);
> + csg_slot = &sched->csg_slots[group->csg_id];
> +
> + if (csg_slot->priority != new_csg_prio) {
> + panthor_fw_csg_endpoint_req_update(ptdev, csg_iface,
> + CSG_EP_REQ_PRIORITY(new_csg_prio),
> + CSG_EP_REQ_PRIORITY_MASK);
> + csgs_upd_ctx_queue_reqs(ptdev, upd_ctx, group->csg_id,
> + csg_iface->output->ack ^ CSG_ENDPOINT_CONFIG,
> + CSG_ENDPOINT_CONFIG);
> + }
> +}
> +
> +static int
> +tick_ctx_schedule_group(struct panthor_scheduler *sched,
> + struct panthor_csg_slots_upd_ctx *upd_ctx,
> + struct panthor_group *group,
> + int csg_id, int csg_prio)
> +{
> + struct panthor_device *ptdev = sched->ptdev;
> + struct panthor_fw_csg_iface *csg_iface =
> + panthor_fw_get_csg_iface(ptdev, csg_id);
> + int ret;
> +
> + ret = group_bind_locked(group, csg_id);
> + if (ret)
> + return ret;
> +
> + csg_slot_prog_locked(ptdev, csg_id, csg_prio);
> +
> + csgs_upd_ctx_queue_reqs(ptdev, upd_ctx, csg_id,
> + group->state == PANTHOR_CS_GROUP_SUSPENDED ?
> + CSG_STATE_RESUME : CSG_STATE_START,
> + CSG_STATE_MASK);
> + csgs_upd_ctx_queue_reqs(ptdev, upd_ctx, csg_id,
> + csg_iface->output->ack ^ CSG_ENDPOINT_CONFIG,
> + CSG_ENDPOINT_CONFIG);
> +
> + return 0;
> +}
> +
> static void
> tick_ctx_apply(struct panthor_scheduler *sched, struct panthor_sched_tick_ctx *ctx)
> {
> struct panthor_group *group, *tmp;
> struct panthor_device *ptdev = sched->ptdev;
> - struct panthor_csg_slot *csg_slot;
> int prio, new_csg_prio = MAX_CSG_PRIO, i;
> u32 free_csg_slots = 0;
> struct panthor_csg_slots_upd_ctx upd_ctx;
> @@ -2359,44 +2428,13 @@ tick_ctx_apply(struct panthor_scheduler *sched, struct panthor_sched_tick_ctx *c
>
> for (prio = PANTHOR_CSG_PRIORITY_COUNT - 1; prio >= 0; prio--) {
> /* Suspend or terminate evicted groups. */
> - list_for_each_entry(group, &ctx->old_groups[prio], run_node) {
> - bool term = !group_can_run(group);
> - int csg_id = group->csg_id;
> -
> - if (drm_WARN_ON(&ptdev->base, csg_id < 0))
> - continue;
> -
> - csg_slot = &sched->csg_slots[csg_id];
> - csgs_upd_ctx_queue_reqs(ptdev, &upd_ctx, csg_id,
> - term ? CSG_STATE_TERMINATE : CSG_STATE_SUSPEND,
> - CSG_STATE_MASK);
> - }
> + list_for_each_entry(group, &ctx->old_groups[prio], run_node)
> + tick_ctx_evict_group(sched, &upd_ctx, group);
>
> /* Update priorities on already running groups. */
> - list_for_each_entry(group, &ctx->groups[prio], run_node) {
> - struct panthor_fw_csg_iface *csg_iface;
> - int csg_id = group->csg_id;
> -
> - if (csg_id < 0) {
> - new_csg_prio--;
> - continue;
> - }
> -
> - csg_slot = &sched->csg_slots[csg_id];
> - csg_iface = panthor_fw_get_csg_iface(ptdev, csg_id);
> - if (csg_slot->priority == new_csg_prio) {
> - new_csg_prio--;
> - continue;
> - }
> -
> - panthor_fw_csg_endpoint_req_update(ptdev, csg_iface,
> - CSG_EP_REQ_PRIORITY(new_csg_prio),
> - CSG_EP_REQ_PRIORITY_MASK);
> - csgs_upd_ctx_queue_reqs(ptdev, &upd_ctx, csg_id,
> - csg_iface->output->ack ^ CSG_ENDPOINT_CONFIG,
> - CSG_ENDPOINT_CONFIG);
> - new_csg_prio--;
> - }
> + list_for_each_entry(group, &ctx->groups[prio], run_node)
> + tick_ctx_update_group_prio(sched, &upd_ctx, group,
> + new_csg_prio--);
> }
>
> ret = csgs_upd_ctx_apply_locked(ptdev, &upd_ctx);
> @@ -2424,34 +2462,23 @@ tick_ctx_apply(struct panthor_scheduler *sched, struct panthor_sched_tick_ctx *c
> for (prio = PANTHOR_CSG_PRIORITY_COUNT - 1; prio >= 0; prio--) {
> list_for_each_entry(group, &ctx->groups[prio], run_node) {
> int csg_id = group->csg_id;
> - struct panthor_fw_csg_iface *csg_iface;
> + int csg_prio = new_csg_prio--;
>
> - if (csg_id >= 0) {
> - new_csg_prio--;
> + if (csg_id >= 0)
> continue;
> - }
>
> csg_id = ffs(free_csg_slots) - 1;
> if (drm_WARN_ON(&ptdev->base, csg_id < 0))
> break;
>
> - csg_iface = panthor_fw_get_csg_iface(ptdev, csg_id);
> - csg_slot = &sched->csg_slots[csg_id];
> - ret = group_bind_locked(group, csg_id);
> + ret = tick_ctx_schedule_group(sched, &upd_ctx, group,
> + csg_id, csg_prio);
> if (ret) {
> panthor_device_schedule_reset(ptdev);
> ctx->csg_upd_failed_mask |= BIT(csg_id);
> return;
> }
>
> - csg_slot_prog_locked(ptdev, csg_id, new_csg_prio--);
> - csgs_upd_ctx_queue_reqs(ptdev, &upd_ctx, csg_id,
> - group->state == PANTHOR_CS_GROUP_SUSPENDED ?
> - CSG_STATE_RESUME : CSG_STATE_START,
> - CSG_STATE_MASK);
> - csgs_upd_ctx_queue_reqs(ptdev, &upd_ctx, csg_id,
> - csg_iface->output->ack ^ CSG_ENDPOINT_CONFIG,
> - CSG_ENDPOINT_CONFIG);
> free_csg_slots &= ~BIT(csg_id);
> }
> }