drm/panfrost: Clear MMU irqs before handling the fault

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@vger.kernel.org>
Fixes: 187d2929206e ("drm/panfrost: Add support for GPU heap allocations")
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210205111757.585248-2-boris.brezillon@collabora.com

diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
index 7c1b3481b78506e3090984ebd4608438dbb5fd6f..904d634508626b9e666729d989583b6275a7a035 100644 (file)
--- 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;
        }