[PATCH 5.11 064/601] drm/panfrost: Clear MMU irqs before handling the fault

Greg Kroah-Hartman
2021-05-12T16:53:26Z

From: Boris Brezillon <boris.brezillon@collabora.com>

commit 3aa0a80fc692c9959c261f4c5bfe9c23ddd90562 upstream.

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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/panfrost/panfrost_mmu.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- 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_hand
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_hand
access_type, access_type_name(pfdev, fault_status),
source_id);

- mmu_write(pfdev, MMU_INT_CLEAR, mask);
-
status &= ~mask;
}