On 01/02/2021 08:21, Boris Brezillon wrote:
When a fault is handled it will unblock the GPU which will continue
executing its shader and might fault almost immediately on a different
page. If we clear interrupts after handling the fault we might miss new
faults, so clear them before.
Cc: <stable@xxxxxxxxxxxxxxx>
Fixes: 187d2929206e ("drm/panfrost: Add support for GPU heap allocations")
Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
Good catch (although this oddly rings a bell - so perhaps it was me you
discussed it with before)
Reviewed-by: Steven Price <steven.price@xxxxxxx>
---
drivers/gpu/drm/panfrost/panfrost_mmu.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
index 7c1b3481b785..904d63450862 100644
--- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
+++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
@@ -593,6 +593,8 @@ static irqreturn_t panfrost_mmu_irq_handler_thread(int irq, void *data)
access_type = (fault_status >> 8) & 0x3;
source_id = (fault_status >> 16);
+ mmu_write(pfdev, MMU_INT_CLEAR, mask);
+
/* Page fault only */
ret = -1;
if ((status & mask) == BIT(i) && (exception_type & 0xF8) == 0xC0)
@@ -616,8 +618,6 @@ static irqreturn_t panfrost_mmu_irq_handler_thread(int irq, void *data)
access_type, access_type_name(pfdev, fault_status),
source_id);
- mmu_write(pfdev, MMU_INT_CLEAR, mask);
-
status &= ~mask;
}
