[PATCH v9 07/16] drm/panfrost: Explicitly enable MMU interrupts at device init

["Adrián Larumbe" <adrian.larumbe@collabora.com>]

Because the device must be in a position to accept jobs between the time
drm_dev_register() is called and autosuspend first kicks in, there's a very
narrow window inbetween during which jobs targeting the tiler buffer
object would time out, since the device's PM status is 'Active', but no MMU
interrupts were enabled at device initialisation time.

Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
Fixes: 73e467f60acd ("drm/panfrost: Consolidate reset handling")
---
 drivers/gpu/drm/panfrost/panfrost_mmu.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
index 5c393ed6e310..faa62643caf1 100644
--- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
+++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
@@ -336,6 +336,12 @@ void panfrost_mmu_as_put(struct panfrost_device *pfdev, struct panfrost_mmu *mmu
 	WARN_ON(atomic_read(&mmu->as_count) < 0);
 }
 
+static void panfrost_mmu_enable_interrupts(struct panfrost_device *pfdev)
+{
+	mmu_write(pfdev, MMU_INT_CLEAR, ~0);
+	mmu_write(pfdev, MMU_INT_MASK, ~0);
+}
+
 void panfrost_mmu_reset(struct panfrost_device *pfdev)
 {
 	struct panfrost_mmu *mmu, *mmu_tmp;
@@ -355,8 +361,7 @@ void panfrost_mmu_reset(struct panfrost_device *pfdev)
 
 	spin_unlock(&pfdev->as_lock);
 
-	mmu_write(pfdev, MMU_INT_CLEAR, ~0);
-	mmu_write(pfdev, MMU_INT_MASK, ~0);
+	panfrost_mmu_enable_interrupts(pfdev);
 }
 
 static size_t get_pgsize(u64 addr, size_t size, size_t *count)
@@ -973,6 +978,8 @@ int panfrost_mmu_init(struct panfrost_device *pfdev)
 		return err;
 	}
 
+	panfrost_mmu_enable_interrupts(pfdev);
+
 	return 0;
 }
 

-- 
2.55.0