[PATCH] drm/msm/adreno: warn if chip revn is verified before being set

[Stephen Boyd]

Quoting Dmitry Baryshkov (2023-04-10 15:38:36)
> The commit 010c8bbad2cb ("drm: msm: adreno: Disable preemption on Adreno
> 510") tried to check GPU's revn before revn being set. Add WARN_ON_ONCE
> to prevent such bugs from happening again. A separate helper is
> necessary so that the warning is displayed really just once instead of
> being displayed for each of comparisons.
>
> Suggested-by: Stephen Boyd <swboyd at chromium.org>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
> ---
>  drivers/gpu/drm/msm/adreno/adreno_gpu.h | 63 ++++++++++++++++---------
>  1 file changed, 40 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.h b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> index f62612a5c70f..47e21d44ac24 100644
> --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
> @@ -145,40 +145,51 @@ struct adreno_platform_config {
>
>  bool adreno_cmp_rev(struct adreno_rev rev1, struct adreno_rev rev2);
>
> +static inline bool adreno_cmp_revn(struct adreno_gpu *gpu, uint32_t revn)

'cmp' in the name makes me think it's comparing. Maybe 'is' is better
because we're testing for equality.

	adreno_is_revn()

Also 'const struct adreno_gpu *' because it isn't changing?

> +{
> +       WARN_ON_ONCE(!gpu->revn);
> +
> +       return gpu->revn == revn;
> +}
> +
>  static inline bool adreno_is_a2xx(struct adreno_gpu *gpu)

And then these can all be const in a followup patch probably.