[PATCH] drm: msm: adreno: Disable preemption on Adreno 510

[Adam Skladowski]

Downstream driver appears to not support preemption on A510 target,
trying to use one make device slow and fill log with rings related errors.
Set num_rings to 1 to disable preemption.

Suggested-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
Fixes: e20c9284c8f2 ("drm/msm/adreno: Add support for Adreno 510 GPU")
Signed-off-by: Adam Skladowski <a39.skl at gmail.com>
---
 drivers/gpu/drm/msm/adreno/a5xx_gpu.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
index d09221f97f71..074b4e9a8500 100644
--- a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
@@ -1743,6 +1743,7 @@ struct msm_gpu *a5xx_gpu_init(struct drm_device *dev)
 	struct a5xx_gpu *a5xx_gpu = NULL;
 	struct adreno_gpu *adreno_gpu;
 	struct msm_gpu *gpu;
+	unsigned int nr_rings;
 	int ret;
 
 	if (!pdev) {
@@ -1763,7 +1764,12 @@ struct msm_gpu *a5xx_gpu_init(struct drm_device *dev)
 
 	check_speed_bin(&pdev->dev);
 
-	ret = adreno_gpu_init(dev, pdev, adreno_gpu, &funcs, 4);
+	nr_rings = 4;
+
+	if (adreno_is_a510(adreno_gpu))
+		nr_rings = 1;
+
+	ret = adreno_gpu_init(dev, pdev, adreno_gpu, &funcs, nr_rings);
 	if (ret) {
 		a5xx_destroy(&(a5xx_gpu->base.base));
 		return ERR_PTR(ret);
-- 
2.25.1