Re: [PATCH v2] drm/msm: handle for EPROBE_DEFER for of_icc_get

[Rob Clark]

On Thu, Jul 9, 2020 at 7:35 AM Jonathan Marek <jonathan@xxxxxxxx> wrote:
>
> Check for errors instead of silently not using icc if the msm driver
> probes before the interconnect driver.
>
> Allow ENODATA for ocmem path, as it is optional and this error
> is returned when "gfx-mem" path is provided but not "ocmem".
>
> Remove the WARN_ON in msm_gpu_cleanup because INIT_LIST_HEAD won't have
> been called on the list yet when going through the defer error path.
>
> Changes in v2:
> * Changed to not only check for EPROBE_DEFER
>
> Signed-off-by: Jonathan Marek <jonathan@xxxxxxxx>
> ---
>  drivers/gpu/drm/msm/adreno/adreno_gpu.c | 17 ++++++++++++++---
>  drivers/gpu/drm/msm/msm_gpu.c           |  2 --
>  2 files changed, 14 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> index 89673c7ed473..0f5217202eb5 100644
> --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> @@ -940,12 +940,20 @@ static int adreno_get_pwrlevels(struct device *dev,
>                  */
>                 gpu->icc_path = of_icc_get(dev, NULL);
>         }
> -       if (IS_ERR(gpu->icc_path))
> +       if (IS_ERR(gpu->icc_path)) {
> +               ret = PTR_ERR(gpu->icc_path);
>                 gpu->icc_path = NULL;
> +               return ret;
> +       }
>
>         gpu->ocmem_icc_path = of_icc_get(dev, "ocmem");
> -       if (IS_ERR(gpu->ocmem_icc_path))
> +       if (IS_ERR(gpu->ocmem_icc_path)) {
> +               ret = PTR_ERR(gpu->ocmem_icc_path);
>                 gpu->ocmem_icc_path = NULL;
> +               /* allow -ENODATA, ocmem icc is optional */
> +               if (ret != -ENODATA)
> +                       return ret;
> +       }
>
>         return 0;
>  }
> @@ -996,6 +1004,7 @@ int adreno_gpu_init(struct drm_device *drm, struct platform_device *pdev,
>         struct adreno_platform_config *config = pdev->dev.platform_data;
>         struct msm_gpu_config adreno_gpu_config  = { 0 };
>         struct msm_gpu *gpu = &adreno_gpu->base;
> +       int ret;
>
>         adreno_gpu->funcs = funcs;
>         adreno_gpu->info = adreno_info(config->rev);
> @@ -1007,7 +1016,9 @@ int adreno_gpu_init(struct drm_device *drm, struct platform_device *pdev,
>
>         adreno_gpu_config.nr_rings = nr_rings;
>
> -       adreno_get_pwrlevels(&pdev->dev, gpu);
> +       ret = adreno_get_pwrlevels(&pdev->dev, gpu);
> +       if (ret)
> +               return ret;
>
>         pm_runtime_set_autosuspend_delay(&pdev->dev,
>                 adreno_gpu->info->inactive_period);
> diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
> index a22d30622306..ccf9a0dd9706 100644
> --- a/drivers/gpu/drm/msm/msm_gpu.c
> +++ b/drivers/gpu/drm/msm/msm_gpu.c
> @@ -959,8 +959,6 @@ void msm_gpu_cleanup(struct msm_gpu *gpu)
>
>         DBG("%s", gpu->name);
>
> -       WARN_ON(!list_empty(&gpu->active_list));
> -

hmm, not a huge fan of removing the WARN_ON().. can we just init the
list head earlier?

BR,
-R

>         for (i = 0; i < ARRAY_SIZE(gpu->rb); i++) {
>                 msm_ringbuffer_destroy(gpu->rb[i]);
>                 gpu->rb[i] = NULL;
> --
> 2.26.1
>