2023-03-14 22:20:26

by Adam Skladowski

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

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 <[email protected]>
Fixes: e20c9284c8f2 ("drm/msm/adreno: Add support for Adreno 510 GPU")
Signed-off-by: Adam Skladowski <[email protected]>
---
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

2023-03-16 10:29:35

by Dmitry Baryshkov

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

On 15/03/2023 00:17, Adam Skladowski wrote:
> 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 <[email protected]>
> Fixes: e20c9284c8f2 ("drm/msm/adreno: Add support for Adreno 510 GPU")
> Signed-off-by: Adam Skladowski <[email protected]>

Reviewed-by: Dmitry Baryshkov <[email protected]>

--
With best wishes
Dmitry