drm: msm: adreno: Disable preemption on Adreno 510

[ Upstream commit 010c8bb ]

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@linaro.org>
Fixes: e20c928 ("drm/msm/adreno: Add support for Adreno 510 GPU")
Signed-off-by: Adam Skladowski <a39.skl@gmail.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/526898/
Link: https://lore.kernel.org/r/20230314221757.13096-1-a39.skl@gmail.com
Signed-off-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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);