Re: [PATCH 7/8] drm/rockchip: vop2: Keep the other LUT_PORT_SEL fields on gamma LUT updates

[Chaoyi Chen <chaoyi.chen@rock-chips.com>]

On 11/10/2026 3:18 PM, Arun Iyengar via B4 Relay wrote:
> From: Arun Iyengar <aiyengar1990@gmail.com>
> 
> On RK3588 the gamma LUT of a video port is written through a window that
> GAMMA_AHB_WRITE_SEL in SYS_CTRL_LUT_PORT_SEL selects. The register also
> holds the dclk source selection of video ports 0 and 2 and the enable of
> the video port 0/1 merge for modes wider than 4096 pixels, which writing
> the whole register clears.
> 
> Only update the write select field.
> 
> Signed-off-by: Arun Iyengar <aiyengar1990@gmail.com>

Reviewed-by: Chaoyi Chen <chaoyi.chen@rock-chips.com>

> ---
>  drivers/gpu/drm/rockchip/rockchip_drm_vop2.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
> index 3323e50224c5..9ad138457204 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
> @@ -1774,8 +1774,9 @@ static void vop2_crtc_atomic_set_gamma_seamless(struct vop2 *vop2,
>  						struct vop2_video_port *vp,
>  						struct drm_crtc *crtc)
>  {
> -	vop2_writel(vop2, RK3568_LUT_PORT_SEL,
> -		    FIELD_PREP(RK3588_LUT_PORT_SEL__GAMMA_AHB_WRITE_SEL, vp->id));
> +	regmap_update_bits(vop2->map, RK3568_LUT_PORT_SEL,
> +			   RK3588_LUT_PORT_SEL__GAMMA_AHB_WRITE_SEL,
> +			   FIELD_PREP(RK3588_LUT_PORT_SEL__GAMMA_AHB_WRITE_SEL, vp->id));
>  	vop2_vp_dsp_lut_enable(vp);
>  	vop2_crtc_write_gamma_lut(vop2, crtc);
>  	vop2_vp_dsp_lut_update_enable(vp);
> 

-- 
Best, 
Chaoyi