[Intel-gfx] [PATCH 1/2] drm/i915/display/vlv: fix pixel overlap register update

[Jani Nikula]

On Mon, 19 Dec 2022, Andrzej Hajda <andrzej.hajda at intel.com> wrote:
> To update properly bits in the register the mask should be used
> to clear old value and then the result should be or-ed with new
> value, for such updates there is separate helper intel_de_rmw.
>
> Signed-off-by: Andrzej Hajda <andrzej.hajda at intel.com>

Seems like the right thing to do.

Reviewed-by: Jani Nikula <jani.nikula at intel.com>


> ---
>  drivers/gpu/drm/i915/display/vlv_dsi.c | 24 +++++++++---------------
>  1 file changed, 9 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/vlv_dsi.c b/drivers/gpu/drm/i915/display/vlv_dsi.c
> index 662bdb656aa304..f5268997a3e172 100644
> --- a/drivers/gpu/drm/i915/display/vlv_dsi.c
> +++ b/drivers/gpu/drm/i915/display/vlv_dsi.c
> @@ -649,23 +649,17 @@ static void intel_dsi_port_enable(struct intel_encoder *encoder,
>  	enum port port;
>  
>  	if (intel_dsi->dual_link == DSI_DUAL_LINK_FRONT_BACK) {
> -		u32 temp;
> +		u32 temp = intel_dsi->pixel_overlap;
> +
>  		if (IS_GEMINILAKE(dev_priv) || IS_BROXTON(dev_priv)) {
> -			for_each_dsi_port(port, intel_dsi->ports) {
> -				temp = intel_de_read(dev_priv,
> -						     MIPI_CTRL(port));
> -				temp &= ~BXT_PIXEL_OVERLAP_CNT_MASK |
> -					intel_dsi->pixel_overlap <<
> -					BXT_PIXEL_OVERLAP_CNT_SHIFT;
> -				intel_de_write(dev_priv, MIPI_CTRL(port),
> -					       temp);
> -			}
> +			for_each_dsi_port(port, intel_dsi->ports)
> +				intel_de_rmw(dev_priv, MIPI_CTRL(port),
> +					     BXT_PIXEL_OVERLAP_CNT_MASK,
> +					     temp << BXT_PIXEL_OVERLAP_CNT_SHIFT);
>  		} else {
> -			temp = intel_de_read(dev_priv, VLV_CHICKEN_3);
> -			temp &= ~PIXEL_OVERLAP_CNT_MASK |
> -					intel_dsi->pixel_overlap <<
> -					PIXEL_OVERLAP_CNT_SHIFT;
> -			intel_de_write(dev_priv, VLV_CHICKEN_3, temp);
> +			intel_de_rmw(dev_priv, VLV_CHICKEN_3,
> +				     PIXEL_OVERLAP_CNT_MASK,
> +				     temp << PIXEL_OVERLAP_CNT_SHIFT);
>  		}
>  	}

-- 
Jani Nikula, Intel Open Source Graphics Center