[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <203a2b93-a842-8cf2-b265-864f520c16a6@baylibre.com>
Date: Wed, 6 Apr 2022 11:20:16 +0200
From: Neil Armstrong <narmstrong@...libre.com>
To: Sandor.yu@....com, dri-devel@...ts.freedesktop.org,
linux-kernel@...r.kernel.org, andrzej.hajda@...el.com,
robert.foss@...aro.org, Laurent.pinchart@...asonboard.com,
jonas@...boo.se, jernej.skrabec@...il.com
Cc: shengjiu.wang@....com, cai.huoqing@...ux.dev, maxime@...no.tech,
harry.wentland@....com, hverkuil-cisco@...all.nl,
amuel@...lland.org
Subject: Re: [PATCH v1 3/5] drm: bridge: dw_hdmi: Enable GCP only for Deep
Color
On 06/04/2022 10:48, Sandor.yu@....com wrote:
> From: Sandor Yu <Sandor.yu@....com>
>
> HDMI1.4b specification section 6.5.3:
> Source shall only send GCPs with non-zero CD to sinks
> that indicate support for Deep Color.
>
> DW HDMI GPC default enabled, clear gpc_auto bit for bpp 24.
>
> Signed-off-by: Sandor Yu <Sandor.yu@....com>
> ---
> drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> index b11577de4836..c7b11582529e 100644
> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
> @@ -1160,6 +1160,14 @@ static void hdmi_video_packetize(struct dw_hdmi *hdmi)
> HDMI_VP_PR_CD_DESIRED_PR_FACTOR_MASK);
> hdmi_writeb(hdmi, val, HDMI_VP_PR_CD);
>
> + val = hdmi_readb(hdmi, HDMI_FC_DATAUTO3);
> + if (color_depth == 4)
> + /* disable Auto GCP when bpp 24 */
> + val &= ~0x4;
> + else
> + val |= 0x4;
> + hdmi_writeb(hdmi, val, HDMI_FC_DATAUTO3);
> +
> hdmi_modb(hdmi, HDMI_VP_STUFF_PR_STUFFING_STUFFING_MODE,
> HDMI_VP_STUFF_PR_STUFFING_MASK, HDMI_VP_STUFF);
>
Do you handle the case when color_depth == 0 when output is YUV422 ?
Neil
Powered by blists - more mailing lists