[PATCH] drm/radeon: replace min/max nesting with clamp()

[PATCH] drm/radeon: replace min/max nesting with clamp()

[Xichao Zhao]

The clamp() macro explicitly expresses the intent of constraining
a value within bounds.Therefore, replacing min(max(a, b), c) and
max(min(a,b),c) with clamp(val, lo, hi) can improve code readability.

Signed-off-by: Xichao Zhao <zhao.xichao@vivo.com>
---
 drivers/gpu/drm/radeon/radeon_display.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c
index b4bf5dfeea2d..d66c1a30df95 100644
--- a/drivers/gpu/drm/radeon/radeon_display.c
+++ b/drivers/gpu/drm/radeon/radeon_display.c
@@ -926,10 +926,10 @@ static void avivo_get_fb_ref_div(unsigned nom, unsigned den, unsigned post_div,
 				 unsigned *fb_div, unsigned *ref_div)
 {
 	/* limit reference * post divider to a maximum */
-	ref_div_max = max(min(100 / post_div, ref_div_max), 1u);
+	ref_div_max = clamp(100 / post_div, 1u, ref_div_max);
 
 	/* get matching reference and feedback divider */
-	*ref_div = min(max(den/post_div, 1u), ref_div_max);
+	*ref_div = clamp(den / post_div, 1u, ref_div_max);
 	*fb_div = DIV_ROUND_CLOSEST(nom * *ref_div * post_div, den);
 
 	/* limit fb divider to its maximum */
-- 
2.34.1

Re: [PATCH] drm/radeon: replace min/max nesting with clamp()

[Christian König]

On 12.08.25 05:16, Xichao Zhao wrote:
> The clamp() macro explicitly expresses the intent of constraining
> a value within bounds.Therefore, replacing min(max(a, b), c) and
> max(min(a,b),c) with clamp(val, lo, hi) can improve code readability.
> 
> Signed-off-by: Xichao Zhao <zhao.xichao@vivo.com>

Reviewed-by: Christian König <christian.koenig@amd.com>

> ---
>  drivers/gpu/drm/radeon/radeon_display.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c
> index b4bf5dfeea2d..d66c1a30df95 100644
> --- a/drivers/gpu/drm/radeon/radeon_display.c
> +++ b/drivers/gpu/drm/radeon/radeon_display.c
> @@ -926,10 +926,10 @@ static void avivo_get_fb_ref_div(unsigned nom, unsigned den, unsigned post_div,
>  				 unsigned *fb_div, unsigned *ref_div)
>  {
>  	/* limit reference * post divider to a maximum */
> -	ref_div_max = max(min(100 / post_div, ref_div_max), 1u);
> +	ref_div_max = clamp(100 / post_div, 1u, ref_div_max);
>  
>  	/* get matching reference and feedback divider */
> -	*ref_div = min(max(den/post_div, 1u), ref_div_max);
> +	*ref_div = clamp(den / post_div, 1u, ref_div_max);
>  	*fb_div = DIV_ROUND_CLOSEST(nom * *ref_div * post_div, den);
>  
>  	/* limit fb divider to its maximum */

Re: [PATCH] drm/radeon: replace min/max nesting with clamp()

[Alex Deucher]

Applied.  Thanks!

Alex

On Tue, Aug 12, 2025 at 2:49 AM Christian König
<christian.koenig@amd.com> wrote:
>
> On 12.08.25 05:16, Xichao Zhao wrote:
> > The clamp() macro explicitly expresses the intent of constraining
> > a value within bounds.Therefore, replacing min(max(a, b), c) and
> > max(min(a,b),c) with clamp(val, lo, hi) can improve code readability.
> >
> > Signed-off-by: Xichao Zhao <zhao.xichao@vivo.com>
>
> Reviewed-by: Christian König <christian.koenig@amd.com>
>
> > ---
> >  drivers/gpu/drm/radeon/radeon_display.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c
> > index b4bf5dfeea2d..d66c1a30df95 100644
> > --- a/drivers/gpu/drm/radeon/radeon_display.c
> > +++ b/drivers/gpu/drm/radeon/radeon_display.c
> > @@ -926,10 +926,10 @@ static void avivo_get_fb_ref_div(unsigned nom, unsigned den, unsigned post_div,
> >                                unsigned *fb_div, unsigned *ref_div)
> >  {
> >       /* limit reference * post divider to a maximum */
> > -     ref_div_max = max(min(100 / post_div, ref_div_max), 1u);
> > +     ref_div_max = clamp(100 / post_div, 1u, ref_div_max);
> >
> >       /* get matching reference and feedback divider */
> > -     *ref_div = min(max(den/post_div, 1u), ref_div_max);
> > +     *ref_div = clamp(den / post_div, 1u, ref_div_max);
> >       *fb_div = DIV_ROUND_CLOSEST(nom * *ref_div * post_div, den);
> >
> >       /* limit fb divider to its maximum */
>