[PATCH 07/10] drm/panthor: Automate CSG IRQ processing at group unbind time

Boris Brezillon
2026-04-29T09:39:16Z

Make the sched_process_csg_irq_locked() call part of
group_unbind_locked() so we don't have to manually call it in
tick_ctx_apply()/panthor_sched_suspend().

This implies moving group_[un]bind_locked() around to avoid a
forward declaration.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
---
drivers/gpu/drm/panthor/panthor_sched.c | 178 +++++++++++++++-----------------
1 file changed, 82 insertions(+), 96 deletions(-)

diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c
index c197bdc4b2c7..601a9bff1485 100644
--- a/drivers/gpu/drm/panthor/panthor_sched.c
+++ b/drivers/gpu/drm/panthor/panthor_sched.c
@@ -982,86 +982,6 @@ group_get(struct panthor_group *group)
return group;
}

-/**
- * group_bind_locked() - Bind a group to a group slot
- * @group: Group.
- * @csg_id: Slot.
- *
- * Return: 0 on success, a negative error code otherwise.
- */
-static int
-group_bind_locked(struct panthor_group *group, u32 csg_id)
-{
- struct panthor_device *ptdev = group->ptdev;
- int ret;
-
- lockdep_assert_held(&ptdev->scheduler->lock);
-
- if (drm_WARN_ON(&ptdev->base, group->csg_id != -1 || csg_id >= MAX_CSGS ||
- ptdev->scheduler->csg_slots[csg_id].group))
- return -EINVAL;
-
- ret = panthor_vm_active(group->vm);
- if (ret)
- return ret;
-
- group_get(group);
-
- /* Dummy doorbell allocation: doorbell is assigned to the group and
- * all queues use the same doorbell.
- *
- * TODO: Implement LRU-based doorbell assignment, so the most often
- * updated queues get their own doorbell, thus avoiding useless checks
- * on queues belonging to the same group that are rarely updated.
- */
- for (u32 i = 0; i < group->queue_count; i++)
- group->queues[i]->doorbell_id = csg_id + 1;
-
- scoped_guard(spinlock_irqsave, &ptdev->scheduler->events_lock) {
- ptdev->scheduler->csg_slots[csg_id].group = group;
- group->csg_id = csg_id;
- }
-
- return 0;
-}
-
-/**
- * group_unbind_locked() - Unbind a group from a slot.
- * @group: Group to unbind.
- *
- * Return: 0 on success, a negative error code otherwise.
- */
-static int
-group_unbind_locked(struct panthor_group *group)
-{
- struct panthor_device *ptdev = group->ptdev;
-
- lockdep_assert_held(&ptdev->scheduler->lock);
-
- if (drm_WARN_ON(&ptdev->base, group->csg_id < 0 || group->csg_id >= MAX_CSGS))
- return -EINVAL;
-
- if (drm_WARN_ON(&ptdev->base, group->state == PANTHOR_CS_GROUP_ACTIVE))
- return -EINVAL;
-
- scoped_guard(spinlock_irqsave, &ptdev->scheduler->events_lock) {
- ptdev->scheduler->csg_slots[group->csg_id].group = NULL;
- group->csg_id = -1;
- }
-
- panthor_vm_idle(group->vm);
-
- /* Tiler OOM events will be re-issued next time the group is scheduled. */
- atomic_set(&group->tiler_oom, 0);
- cancel_work(&group->tiler_oom_work);
-
- for (u32 i = 0; i < group->queue_count; i++)
- group->queues[i]->doorbell_id = -1;
-
- group_put(group);
- return 0;
-}
-
static bool
group_is_idle(struct panthor_group *group)
{
@@ -1968,6 +1888,88 @@ void panthor_sched_report_fw_events(struct panthor_device *ptdev, u32 events)
}
}

+/**
+ * group_bind_locked() - Bind a group to a group slot
+ * @group: Group.
+ * @csg_id: Slot.
+ *
+ * Return: 0 on success, a negative error code otherwise.
+ */
+static int
+group_bind_locked(struct panthor_group *group, u32 csg_id)
+{
+ struct panthor_device *ptdev = group->ptdev;
+ int ret;
+
+ lockdep_assert_held(&ptdev->scheduler->lock);
+
+ if (drm_WARN_ON(&ptdev->base, group->csg_id != -1 || csg_id >= MAX_CSGS ||
+ ptdev->scheduler->csg_slots[csg_id].group))
+ return -EINVAL;
+
+ ret = panthor_vm_active(group->vm);
+ if (ret)
+ return ret;
+
+ group_get(group);
+
+ /* Dummy doorbell allocation: doorbell is assigned to the group and
+ * all queues use the same doorbell.
+ *
+ * TODO: Implement LRU-based doorbell assignment, so the most often
+ * updated queues get their own doorbell, thus avoiding useless checks
+ * on queues belonging to the same group that are rarely updated.
+ */
+ for (u32 i = 0; i < group->queue_count; i++)
+ group->queues[i]->doorbell_id = csg_id + 1;
+
+ scoped_guard(spinlock_irqsave, &ptdev->scheduler->events_lock) {
+ ptdev->scheduler->csg_slots[csg_id].group = group;
+ group->csg_id = csg_id;
+ }
+
+ return 0;
+}
+
+/**
+ * group_unbind_locked() - Unbind a group from a slot.
+ * @group: Group to unbind.
+ *
+ * Return: 0 on success, a negative error code otherwise.
+ */
+static int
+group_unbind_locked(struct panthor_group *group)
+{
+ struct panthor_device *ptdev = group->ptdev;
+
+ lockdep_assert_held(&ptdev->scheduler->lock);
+
+ if (drm_WARN_ON(&ptdev->base, group->csg_id < 0 || group->csg_id >= MAX_CSGS))
+ return -EINVAL;
+
+ if (drm_WARN_ON(&ptdev->base, group->state == PANTHOR_CS_GROUP_ACTIVE))
+ return -EINVAL;
+
+ scoped_guard(spinlock_irqsave, &ptdev->scheduler->events_lock) {
+ /* Process all pending IRQs before returning the slot. */
+ sched_process_csg_irq_locked(ptdev, group->csg_id);
+ ptdev->scheduler->csg_slots[group->csg_id].group = NULL;
+ group->csg_id = -1;
+ }
+
+ panthor_vm_idle(group->vm);
+
+ /* Tiler OOM events will be re-issued next time the group is scheduled. */
+ atomic_set(&group->tiler_oom, 0);
+ cancel_work(&group->tiler_oom_work);
+
+ for (u32 i = 0; i < group->queue_count; i++)
+ group->queues[i]->doorbell_id = -1;
+
+ group_put(group);
+ return 0;
+}
+
static const char *fence_get_driver_name(struct dma_fence *fence)
{
return "panthor";
@@ -2396,15 +2398,6 @@ tick_ctx_apply(struct panthor_scheduler *sched, struct panthor_sched_tick_ctx *c
/* Unbind evicted groups. */
for (prio = PANTHOR_CSG_PRIORITY_COUNT - 1; prio >= 0; prio--) {
list_for_each_entry(group, &ctx->old_groups[prio], run_node) {
- /* This group is gone. Process interrupts to clear
- * any pending interrupts before we start the new
- * group.
- */
- if (group->csg_id >= 0) {
- guard(spinlock_irqsave)(&sched->events_lock);
- sched_process_csg_irq_locked(ptdev, group->csg_id);
- }
-
group_unbind_locked(group);
}
}
@@ -2970,8 +2963,6 @@ void panthor_sched_suspend(struct panthor_device *ptdev)

if (flush_caches_failed)
csg_slot->group->state = PANTHOR_CS_GROUP_TERMINATED;
- else
- csg_slot_sync_update_locked(ptdev, csg_id);

slot_mask &= ~BIT(csg_id);
}
@@ -2986,11 +2977,6 @@ void panthor_sched_suspend(struct panthor_device *ptdev)

group_get(group);

- if (group->csg_id >= 0) {
- guard(spinlock_irqsave)(&sched->events_lock);
- sched_process_csg_irq_locked(ptdev, group->csg_id);
- }
-
group_unbind_locked(group);

drm_WARN_ON(&group->ptdev->base, !list_empty(&group->run_node));

--
2.53.0