Re: [PATCH] drm/msm: Fix removal of valid error case when checking speed_bin

[Doug Anderson]

Hi,

On Mon, Mar 29, 2021 at 6:34 PM John Stultz <john.stultz@xxxxxxxxxx> wrote:
>
> Commit 7bf168c8fe8c  ("drm/msm: Fix speed-bin support not to
> access outside valid memory"), reworked the nvmem reading of
> "speed_bin", but in doing so dropped handling of the -ENOENT
> case which was previously documented as "fine".
>
> That change resulted in the db845c board display to fail to
> start, with the following error:
>
> adreno 5000000.gpu: [drm:a6xx_gpu_init] *ERROR* failed to read speed-bin (-2). Some OPPs may not be supported by hardware
>
> Thus, this patch simply re-adds the ENOENT handling so the lack
> of the speed_bin entry isn't fatal for display, and gets things
> working on db845c.
>
> Cc: Rob Clark <robdclark@xxxxxxxxx>
> Cc: Sean Paul <sean@xxxxxxxxxx>
> Cc: Jordan Crouse <jcrouse@xxxxxxxxxxxxxx>
> Cc: Eric Anholt <eric@xxxxxxxxxx>
> Cc: Douglas Anderson <dianders@xxxxxxxxxxxx>
> Cc: linux-arm-msm@xxxxxxxxxxxxxxx
> Cc: freedreno@xxxxxxxxxxxxxxxxxxxxx
> Cc: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> Cc: YongQin Liu <yongqin.liu@xxxxxxxxxx>
> Reported-by: YongQin Liu <yongqin.liu@xxxxxxxxxx>
> Fixes: 7bf168c8fe8c  ("drm/msm: Fix speed-bin support not to access outside valid memory")
> Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
> ---
>  drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)

Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>