Re: [PATCH 1/2] drm/msm/dsi: improve/fix dsc pclk calculation

[Konrad Dybcio]

On 5.10.2024 4:38 PM, Jonathan Marek wrote:
> drm_mode_vrefresh() can introduce a large rounding error, avoid it.
> 
> Signed-off-by: Jonathan Marek <jonathan@xxxxxxxx>
> ---
>  drivers/gpu/drm/msm/dsi/dsi_host.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
> index 185d7de0bf376..1205aa398e445 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
> @@ -542,7 +542,7 @@ static unsigned long dsi_adjust_pclk_for_compression(const struct drm_display_mo
>  
>  	int new_htotal = mode->htotal - mode->hdisplay + new_hdisplay;
>  
> -	return new_htotal * mode->vtotal * drm_mode_vrefresh(mode);
> +	return mult_frac(mode->clock * 1000u, new_htotal, mode->htotal);

This seems to ignore mult/div by two on certain mode flags.. is that
intended?

Konrad