[PATCH 1/3] drm/msm/dp: account for widebus in msm_dp_catalog_panel_tpg_enable()

[Dmitry Baryshkov]

On Mon, Dec 02, 2024 at 12:41:58PM -0800, Abhinav Kumar wrote:
> Adjust the h_active calculation to account for widebus in tpg.
> 
> Fixes: 757a2f36ab09 ("drm/msm/dp: enable widebus feature for display port")
> Signed-off-by: Abhinav Kumar <quic_abhinavk at quicinc.com>
> ---
>  drivers/gpu/drm/msm/dp/dp_catalog.c | 14 +++++++++++++-
>  1 file changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.c b/drivers/gpu/drm/msm/dp/dp_catalog.c
> index b4c8856fb25d..05c8e1996f60 100644
> --- a/drivers/gpu/drm/msm/dp/dp_catalog.c
> +++ b/drivers/gpu/drm/msm/dp/dp_catalog.c
> @@ -1011,9 +1011,21 @@ void msm_dp_catalog_panel_tpg_enable(struct msm_dp_catalog *msm_dp_catalog,
>  	u32 v_sync_width;
>  	u32 hsync_ctl;
>  	u32 display_hctl;
> +	u32 h_sync_width;
> +	u32 h_front_porch;
> +	u32 h_back_porch;
> +	u32 h_active;
> +
> +	h_active = drm_mode->hdisplay;
> +	h_back_porch = drm_mode->htotal - drm_mode->hsync_end;
> +	h_sync_width = drm_mode->htotal - (drm_mode->hsync_start + h_back_porch);

It's at least drm_mode->hsync_end - drm_mode->hsync_start

> +	h_front_porch = drm_mode->hsync_start - drm_mode->hdisplay;
> +
> +	if (msm_dp_catalog->wide_bus_en)
> +		h_active /= 2;
>  
>  	/* TPG config parameters*/
> -	hsync_period = drm_mode->htotal;
> +	hsync_period = h_sync_width + h_back_porch + h_active + h_front_porch;

Is it equivalent to:

hsync_period = drm_mode->htotal;
if (msm_dp_catalog->wide_bus_en)
    hsync_period -= drm_mode->hdisplay / 2;

I think it's simpler to handle.

>  	vsync_period = drm_mode->vtotal;
>  
>  	display_v_start = ((drm_mode->vtotal - drm_mode->vsync_start) *
> 
> -- 
> 2.34.1
> 

-- 
With best wishes
Dmitry