On 3/6/23 01:06, Geert Uytterhoeven wrote:
> With gcc-5 and CONFIG_UBSAN_SHIFT=y:
>
> drivers/gpu/drm/msm/msm_mdss.c: In function 'msm_mdss_enable':
> drivers/gpu/drm/msm/msm_mdss.c:296:2: error: case label does not reduce to an integer constant
> case DPU_HW_VER_800:
> ^
> drivers/gpu/drm/msm/msm_mdss.c:299:2: error: case label does not reduce to an integer constant
> case DPU_HW_VER_810:
> ^
> drivers/gpu/drm/msm/msm_mdss.c:300:2: error: case label does not reduce to an integer constant
> case DPU_HW_VER_900:
> ^
>
> This happens because for major revisions 8 or greather, the non-sign bit
> of the major revision number is shifted into bit 31 of a signed integer,
> which is undefined behavior.
>
> Fix this by casting the major revision number to unsigned int.
>
> Fixes: efcd0107727c4f04 ("drm/msm/dpu: add support for SM8550")
> Fixes: 4a352c2fc15aec1e ("drm/msm/dpu: Introduce SC8280XP")
> Fixes: 100d7ef6995d1f86 ("drm/msm/dpu: add support for SM8450")
> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Reviewed-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Thanks.
> ---
> drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
> index ddab9caebb18c40d..bbd3cbdd77956c5d 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
> @@ -19,8 +19,9 @@
> */
> #define MAX_BLOCKS 12
>
> -#define DPU_HW_VER(MAJOR, MINOR, STEP) (((MAJOR & 0xF) << 28) |\
> - ((MINOR & 0xFFF) << 16) |\
> +#define DPU_HW_VER(MAJOR, MINOR, STEP) \
> + ((((unsigned int)MAJOR & 0xF) << 28) | \
> + ((MINOR & 0xFFF) << 16) | \
> (STEP & 0xFFFF))
>
> #define DPU_HW_MAJOR(rev) ((rev) >> 28)
--
~Randy
