On Tue, 19 May 2026, Manikandan Muralidharan wrote:

> Define ATMEL_XLCDC_CLKBYP and set the clock bypass bit on XLCDC
> hardware when the computed divider is less than 2, avoiding an
> invalid divider value. Non-XLCDC hardware retains the existing
> minimum divider clamp of 2.
> 
> Signed-off-by: Manikandan Muralidharan <[email protected]>
> ---
>  drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c | 7 +++++++
>  include/linux/mfd/atmel-hlcdc.h                | 1 +

Acked-by: Lee Jones <[email protected]>

>  2 files changed, 8 insertions(+)
> 
> diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c 
> b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
> index 6da428361c19..f837684654ea 100644
> --- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
> +++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
> @@ -87,6 +87,13 @@ static int atmel_hlcdc_crtc_setup_clock(struct 
> atmel_hlcdc_crtc *crtc,
>  
>       div = DIV_ROUND_CLOSEST(prate, mode_rate);
>       if (div < 2) {
> +             /* XLCDC: bypass divider when div < 2 */
> +             if (crtc->dc->desc->is_xlcdc) {
> +                     *cfg  |= ATMEL_XLCDC_CLKBYP;
> +                     *mask |= ATMEL_XLCDC_CLKBYP;
> +                     return 0;
> +             }
> +             /* Enforce minimum divider for non-XLCDC */
>               div = 2;
>       } else if (ATMEL_HLCDC_CLKDIV(div) & ~ATMEL_HLCDC_CLKDIV_MASK) {
>               /* The divider ended up too big, try a lower base rate. */
> diff --git a/include/linux/mfd/atmel-hlcdc.h b/include/linux/mfd/atmel-hlcdc.h
> index 8e86219293b7..1463c7db0e64 100644
> --- a/include/linux/mfd/atmel-hlcdc.h
> +++ b/include/linux/mfd/atmel-hlcdc.h
> @@ -44,6 +44,7 @@
>  #define ATMEL_XLCDC_HEO_UPDATE               BIT(3)
>  
>  #define ATMEL_HLCDC_CLKPOL           BIT(0)
> +#define ATMEL_XLCDC_CLKBYP           BIT(1)
>  #define ATMEL_HLCDC_CLKSEL           BIT(2)
>  #define ATMEL_HLCDC_CLKPWMSEL                BIT(3)
>  #define ATMEL_HLCDC_CGDIS(i)         BIT(8 + (i))
> -- 
> 2.25.1
> 

-- 
Lee Jones

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