Re: [PATCH v2] drm/msm/a6xx: Fix speed-bin detection vs probe-defer

[Doug Anderson]

Hi,

On Mon, Nov 14, 2022 at 12:50 PM Rob Clark <robdclark@xxxxxxxxx> wrote:
>
> From: Rob Clark <robdclark@xxxxxxxxxxxx>
>
> If we get an error (other than -ENOENT) we need to propagate that up the
> stack.  Otherwise if the nvmem driver hasn't probed yet, we'll end up
> end up claiming that we support all the OPPs which is not likely to be
> true (and on some generations impossible to be true, ie. if there are
> conflicting OPPs).
>
> v2: Update commit msg, gc unused label, etc
>
> Fixed: fe7952c629da ("drm/msm: Add speed-bin support to a618 gpu")
> Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 10 ++++------
>  1 file changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
> index 7fe60c65a1eb..6ae77e88060f 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
> @@ -1941,7 +1941,7 @@ static u32 fuse_to_supp_hw(struct device *dev, struct adreno_rev rev, u32 fuse)
>
>  static int a6xx_set_supported_hw(struct device *dev, struct adreno_rev rev)
>  {
> -       u32 supp_hw = UINT_MAX;
> +       u32 supp_hw;
>         u32 speedbin;
>         int ret;
>
> @@ -1953,15 +1953,13 @@ static int a6xx_set_supported_hw(struct device *dev, struct adreno_rev rev)
>         if (ret == -ENOENT) {
>                 return 0;
>         } else if (ret) {
> -               DRM_DEV_ERROR(dev,
> -                             "failed to read speed-bin (%d). Some OPPs may not be supported by hardware",
> -                             ret);
> -               goto done;
> +               dev_err_probe(dev, ret,
> +                             "failed to read speed-bin. Some OPPs may not be supported by hardware");
> +               return ret;

Both before and after this change, I think you're missing a "\n" at
the end of your error string?

If you want to get even fancier, dev_err_probe is designed to run
"braceless" and returns "ret" as its return value. This you could do:

if (ret == -ENOENT)
  return ret;
else if (ret)
  return dev_err_probe(dev, ret, ...)

After adding the "\n" then either with the extra fanciness or as you have it:

Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>

-Doug