[PATCH v3 4/5] drm/panthor: Let IRQ handlers clear the interrupts themselves
Boris Brezillon
boris.brezillon at collabora.com
Fri Apr 4 08:09:32 UTC 2025
MMU handler needs to be in control of the job interrupt clears because
clearing the interrupt also unblocks the writer/reader that triggered
the fault, and we don't want it to be unblocked until we've had a chance
to process the IRQ.
Since clearing the clearing is just one line, let's make it explicit
instead of doing it in the generic code path.
Note that this commit changes the existing behavior in that the MMU
COMPLETED irqs are no longer cleared, which is fine because they are
masked, so we're not risking an interrupt flood.
Changes in v3:
- Mention the fact we no longer clear MMU COMPLETED irqs
- Add Liviu's R-b
Changes in v2:
- Move the MMU_INT_CLEAR around
Signed-off-by: Boris Brezillon <boris.brezillon at collabora.com>
Reviewed-by: Liviu Dudau <liviu.dudau at arm.com>
---
drivers/gpu/drm/panthor/panthor_device.h | 2 --
drivers/gpu/drm/panthor/panthor_fw.c | 2 ++
drivers/gpu/drm/panthor/panthor_gpu.c | 2 ++
drivers/gpu/drm/panthor/panthor_mmu.c | 7 +++++++
4 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/panthor/panthor_device.h b/drivers/gpu/drm/panthor/panthor_device.h
index da6574021664..4c27b6d85f46 100644
--- a/drivers/gpu/drm/panthor/panthor_device.h
+++ b/drivers/gpu/drm/panthor/panthor_device.h
@@ -383,8 +383,6 @@ static irqreturn_t panthor_ ## __name ## _irq_threaded_handler(int irq, void *da
if (!status) \
break; \
\
- gpu_write(ptdev, __reg_prefix ## _INT_CLEAR, status); \
- \
__handler(ptdev, status); \
ret = IRQ_HANDLED; \
} \
diff --git a/drivers/gpu/drm/panthor/panthor_fw.c b/drivers/gpu/drm/panthor/panthor_fw.c
index 0f52766a3120..446bb377b953 100644
--- a/drivers/gpu/drm/panthor/panthor_fw.c
+++ b/drivers/gpu/drm/panthor/panthor_fw.c
@@ -1008,6 +1008,8 @@ static void panthor_fw_init_global_iface(struct panthor_device *ptdev)
static void panthor_job_irq_handler(struct panthor_device *ptdev, u32 status)
{
+ gpu_write(ptdev, JOB_INT_CLEAR, status);
+
if (!ptdev->fw->booted && (status & JOB_INT_GLOBAL_IF))
ptdev->fw->booted = true;
diff --git a/drivers/gpu/drm/panthor/panthor_gpu.c b/drivers/gpu/drm/panthor/panthor_gpu.c
index 671049020afa..32d678a0114e 100644
--- a/drivers/gpu/drm/panthor/panthor_gpu.c
+++ b/drivers/gpu/drm/panthor/panthor_gpu.c
@@ -150,6 +150,8 @@ static void panthor_gpu_init_info(struct panthor_device *ptdev)
static void panthor_gpu_irq_handler(struct panthor_device *ptdev, u32 status)
{
+ gpu_write(ptdev, GPU_INT_CLEAR, status);
+
if (status & GPU_IRQ_FAULT) {
u32 fault_status = gpu_read(ptdev, GPU_FAULT_STATUS);
u64 address = ((u64)gpu_read(ptdev, GPU_FAULT_ADDR_HI) << 32) |
diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c
index 7cca97d298ea..0ba76982d45b 100644
--- a/drivers/gpu/drm/panthor/panthor_mmu.c
+++ b/drivers/gpu/drm/panthor/panthor_mmu.c
@@ -1710,6 +1710,13 @@ static void panthor_mmu_irq_handler(struct panthor_device *ptdev, u32 status)
access_type, access_type_name(ptdev, fault_status),
source_id);
+ /* We don't handle VM faults at the moment, so let's just clear the
+ * interrupt and let the writer/reader crash.
+ * Note that COMPLETED irqs are never cleared, but this is fine
+ * because they are always masked.
+ */
+ gpu_write(ptdev, MMU_INT_CLEAR, mask);
+
/* Ignore MMU interrupts on this AS until it's been
* re-enabled.
*/
--
2.49.0
More information about the dri-devel
mailing list