[PATCH] drm/amd/display: Don't check for NULL divisor in fixpt code

Alex Hung alex.hung at amd.com
Mon May 5 18:22:51 UTC 2025


Reviewed-by: Alex Hung <alex.hung at amd.com>

On 4/28/25 15:34, Harry Wentland wrote:
> [Why]
> We check for a NULL divisor but don't act on it.
> This check does nothing other than throw a warning.
> It does confuse static checkers though:
> See https://lkml.org/lkml/2025/4/26/371
> 
> [How]
> Drop the ASSERTs in both DC and SPL variants.
> 
> Signed-off-by: Harry Wentland <harry.wentland at amd.com>
> Cc: Linus Torvalds <torvalds at linux-foundation.org>
> Cc: Leo Li <sunpeng.li at amd.com>
> Cc: Alex Deucher <alexander.deucher at amd.com>
> ---
>   drivers/gpu/drm/amd/display/dc/basics/fixpt31_32.c   | 5 -----
>   drivers/gpu/drm/amd/display/dc/sspl/spl_fixpt31_32.c | 4 ----
>   2 files changed, 9 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/dc/basics/fixpt31_32.c b/drivers/gpu/drm/amd/display/dc/basics/fixpt31_32.c
> index 88d3f9d7dd55..452206b5095e 100644
> --- a/drivers/gpu/drm/amd/display/dc/basics/fixpt31_32.c
> +++ b/drivers/gpu/drm/amd/display/dc/basics/fixpt31_32.c
> @@ -51,8 +51,6 @@ static inline unsigned long long complete_integer_division_u64(
>   {
>   	unsigned long long result;
>   
> -	ASSERT(divisor);
> -
>   	result = div64_u64_rem(dividend, divisor, remainder);
>   
>   	return result;
> @@ -213,9 +211,6 @@ struct fixed31_32 dc_fixpt_recip(struct fixed31_32 arg)
>   	 * @note
>   	 * Good idea to use Newton's method
>   	 */
> -
> -	ASSERT(arg.value);
> -
>   	return dc_fixpt_from_fraction(
>   		dc_fixpt_one.value,
>   		arg.value);
> diff --git a/drivers/gpu/drm/amd/display/dc/sspl/spl_fixpt31_32.c b/drivers/gpu/drm/amd/display/dc/sspl/spl_fixpt31_32.c
> index 52d97918a3bd..ebf0287417e0 100644
> --- a/drivers/gpu/drm/amd/display/dc/sspl/spl_fixpt31_32.c
> +++ b/drivers/gpu/drm/amd/display/dc/sspl/spl_fixpt31_32.c
> @@ -29,8 +29,6 @@ static inline unsigned long long spl_complete_integer_division_u64(
>   {
>   	unsigned long long result;
>   
> -	SPL_ASSERT(divisor);
> -
>   	result = spl_div64_u64_rem(dividend, divisor, remainder);
>   
>   	return result;
> @@ -196,8 +194,6 @@ struct spl_fixed31_32 spl_fixpt_recip(struct spl_fixed31_32 arg)
>   	 * Good idea to use Newton's method
>   	 */
>   
> -	SPL_ASSERT(arg.value);
> -
>   	return spl_fixpt_from_fraction(
>   		spl_fixpt_one.value,
>   		arg.value);



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