[PATCH 08/10] drm/panthor: Automatically enable interrupts in panthor_fw_wait_acks()

Boris Brezillon
2026-04-29T09:39:15Z

Rather than assuming an interrupt is always expected for request
acks, temporarily enable the relevant interrupts when the polling-wait
failed. This should hopefully reduce the number of interrupts the CPU
has to process.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
---
drivers/gpu/drm/panthor/panthor_fw.c | 34 +++++++++++++++++++--------------
drivers/gpu/drm/panthor/panthor_sched.c | 5 +++--
2 files changed, 23 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/panthor/panthor_fw.c b/drivers/gpu/drm/panthor/panthor_fw.c
index 8239a6951569..f5e0ceca4130 100644
--- a/drivers/gpu/drm/panthor/panthor_fw.c
+++ b/drivers/gpu/drm/panthor/panthor_fw.c
@@ -1039,16 +1039,10 @@ static void panthor_fw_init_global_iface(struct panthor_device *ptdev)
glb_iface->input->progress_timer = PROGRESS_TIMEOUT_CYCLES >> PROGRESS_TIMEOUT_SCALE_SHIFT;
glb_iface->input->idle_timer = panthor_fw_conv_timeout(ptdev, IDLE_HYSTERESIS_US);

- /* Enable interrupts we care about. */
- glb_iface->input->ack_irq_mask = GLB_CFG_ALLOC_EN |
- GLB_PING |
- GLB_CFG_PROGRESS_TIMER |
- GLB_CFG_POWEROFF_TIMER |
- GLB_IDLE_EN |
- GLB_IDLE;
-
- if (panthor_fw_has_glb_state(ptdev))
- glb_iface->input->ack_irq_mask |= GLB_STATE_MASK;
+ /* Enable interrupts for asynchronous events that are not
+ * triggered by request acks.
+ */
+ glb_iface->input->ack_irq_mask = GLB_IDLE;

panthor_fw_update_reqs(glb_iface, req, GLB_IDLE_EN | GLB_COUNTER_EN,
GLB_IDLE_EN | GLB_COUNTER_EN);
@@ -1318,8 +1312,8 @@ void panthor_fw_unplug(struct panthor_device *ptdev)
* Return: 0 on success, -ETIMEDOUT otherwise.
*/
static int panthor_fw_wait_acks(const u32 *req_ptr, const u32 *ack_ptr,
- wait_queue_head_t *wq,
- u32 req_mask, u32 *acked,
+ u32 *ack_irq_mask_ptr, spinlock_t *lock,
+ wait_queue_head_t *wq, u32 req_mask, u32 *acked,
u32 timeout_ms)
{
u32 ack, req = READ_ONCE(*req_ptr) & req_mask;
@@ -1334,8 +1328,16 @@ static int panthor_fw_wait_acks(const u32 *req_ptr, const u32 *ack_ptr,
if (!ret)
return 0;

- if (wait_event_timeout(*wq, (READ_ONCE(*ack_ptr) & req_mask) == req,
- msecs_to_jiffies(timeout_ms)))
+ scoped_guard(spinlock_irqsave, lock)
+ *ack_irq_mask_ptr |= req_mask;
+
+ ret = wait_event_timeout(*wq, (READ_ONCE(*ack_ptr) & req_mask) == req,
+ msecs_to_jiffies(timeout_ms));
+
+ scoped_guard(spinlock_irqsave, lock)
+ *ack_irq_mask_ptr &= ~req_mask;
+
+ if (ret)
return 0;

/* Check one last time, in case we were not woken up for some reason. */
@@ -1369,6 +1371,8 @@ int panthor_fw_glb_wait_acks(struct panthor_device *ptdev,

return panthor_fw_wait_acks(&glb_iface->input->req,
&glb_iface->output->ack,
+ &glb_iface->input->ack_irq_mask,
+ &glb_iface->lock,
&ptdev->fw->req_waitqueue,
req_mask, acked, timeout_ms);
}
@@ -1395,6 +1399,8 @@ int panthor_fw_csg_wait_acks(struct panthor_device *ptdev, u32 csg_slot,

ret = panthor_fw_wait_acks(&csg_iface->input->req,
&csg_iface->output->ack,
+ &csg_iface->input->ack_irq_mask,
+ &csg_iface->lock,
&ptdev->fw->req_waitqueue,
req_mask, acked, timeout_ms);

diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c
index 601a9bff1485..2edba335f22d 100644
--- a/drivers/gpu/drm/panthor/panthor_sched.c
+++ b/drivers/gpu/drm/panthor/panthor_sched.c
@@ -1110,7 +1110,7 @@ cs_slot_prog_locked(struct panthor_device *ptdev, u32 csg_id, u32 cs_id)
cs_iface->input->ringbuf_output = queue->iface.output_fw_va;
cs_iface->input->config = CS_CONFIG_PRIORITY(queue->priority) |
CS_CONFIG_DOORBELL(queue->doorbell_id);
- cs_iface->input->ack_irq_mask = ~0;
+ cs_iface->input->ack_irq_mask = CS_FATAL | CS_FAULT | CS_TILER_OOM;
panthor_fw_update_reqs(cs_iface, req,
CS_IDLE_SYNC_WAIT |
CS_IDLE_EMPTY |
@@ -1378,7 +1378,8 @@ csg_slot_prog_locked(struct panthor_device *ptdev, u32 csg_id, u32 priority)
csg_iface->input->protm_suspend_buf = 0;
}

- csg_iface->input->ack_irq_mask = ~0;
+ csg_iface->input->ack_irq_mask = CSG_SYNC_UPDATE | CSG_IDLE |
+ CSG_PROGRESS_TIMER_EVENT;
panthor_fw_toggle_reqs(csg_iface, doorbell_req, doorbell_ack, queue_mask);
return 0;
}

--
2.53.0