Re: [PATCH] drm: bridge: dw-hdmi: add HDMI vendor specific infoframe config

From: Andrzej Hajda
Date: Tue Mar 21 2017 - 03:47:42 EST


On 20.03.2017 07:10, Nickey Yang wrote:
> Vendor specific infoframe is mandatory for 4K2K resolution.
> Without this, the HDMI protocol compliance fails.
>
> Signed-off-by: Nickey Yang <nickey.yang@xxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/bridge/dw-hdmi.c | 50 ++++++++++++++++++++++++++++++++++++++++
> drivers/gpu/drm/bridge/dw-hdmi.h | 4 ++++
> 2 files changed, 54 insertions(+)
>
> diff --git a/drivers/gpu/drm/bridge/dw-hdmi.c b/drivers/gpu/drm/bridge/dw-hdmi.c
> index 9a9ec27..79e2e48 100644
> --- a/drivers/gpu/drm/bridge/dw-hdmi.c
> +++ b/drivers/gpu/drm/bridge/dw-hdmi.c
> @@ -1195,6 +1195,55 @@ static void hdmi_config_AVI(struct dw_hdmi *hdmi, struct drm_display_mode *mode)
> hdmi_writeb(hdmi, (frame.right_bar >> 8) & 0xff, HDMI_FC_AVISRB1);
> }
>
> +static void hdmi_config_vendor_specific_infoframe(struct dw_hdmi *hdmi,
> + struct drm_display_mode *mode)
> +{
> + struct hdmi_vendor_infoframe frame;
> + u8 buffer[10];
> + ssize_t err;
> +
> + err = drm_hdmi_vendor_infoframe_from_display_mode(&frame, mode);
> + if (err) {
> + dev_err(hdmi->dev,
> + "Failed to get vendor infoframe from mode: %zd\n", err);
> + return;
> + }
> +
> + err = hdmi_vendor_infoframe_pack(&frame, buffer, sizeof(buffer));
> + if (!err) {
> + dev_err(hdmi->dev, "Failed to pack vendor infoframe: %zd\n",
> + err);
> + return;
> + }

AFAIK function returns number of packed bytes or -EINVAL so the check is
incorrect, and -EINVAL means that there is no need to generate vendor
infoframe, so definitely not dev_err.

> + hdmi_modb(hdmi, 0 << HDMI_FC_DATAUTO0_VSD_OFFSET,
> + HDMI_FC_DATAUTO0_VSD_MASK, HDMI_FC_DATAUTO0);

I see no gain in constructs (0 << HDMI_FC_DATAUTO0_VSD_OFFSET),
additionally mask and offset are redundant (mask == 1 << offset), but it
seems you follow existing practice, so I do not oppose :)

Regards
Andrzej

> +
> + /* Set the length of HDMI vendor specific InfoFrame payload */
> + hdmi_writeb(hdmi, buffer[2], HDMI_FC_VSDSIZE);
> +
> + /* Set 24bit IEEE Registration Identifier */
> + hdmi_writeb(hdmi, buffer[4], HDMI_FC_VSDIEEEID0);
> + hdmi_writeb(hdmi, buffer[5], HDMI_FC_VSDIEEEID1);
> + hdmi_writeb(hdmi, buffer[6], HDMI_FC_VSDIEEEID2);
> +
> + /* Set HDMI_Video_Format and HDMI_VIC/3D_Structure */
> + hdmi_writeb(hdmi, buffer[7], HDMI_FC_VSDPAYLOAD0);
> + hdmi_writeb(hdmi, buffer[8], HDMI_FC_VSDPAYLOAD1);
> +
> + if (frame.s3d_struct >= HDMI_3D_STRUCTURE_SIDE_BY_SIDE_HALF)
> + hdmi_writeb(hdmi, buffer[9], HDMI_FC_VSDPAYLOAD2);
> +
> + /* Packet frame interpolation */
> + hdmi_writeb(hdmi, 1, HDMI_FC_DATAUTO1);
> +
> + /* Auto packets per frame and line spacing */
> + hdmi_writeb(hdmi, 0x11, HDMI_FC_DATAUTO2);
> +
> + /* Configures the Frame Composer On RDRB mode */
> + hdmi_modb(hdmi, 1 << HDMI_FC_DATAUTO0_VSD_OFFSET,
> + HDMI_FC_DATAUTO0_VSD_MASK, HDMI_FC_DATAUTO0);
> +}
> +
> static void hdmi_av_composer(struct dw_hdmi *hdmi,
> const struct drm_display_mode *mode)
> {
> @@ -1446,6 +1495,7 @@ static int dw_hdmi_setup(struct dw_hdmi *hdmi, struct drm_display_mode *mode)
>
> /* HDMI Initialization Step F - Configure AVI InfoFrame */
> hdmi_config_AVI(hdmi, mode);
> + hdmi_config_vendor_specific_infoframe(hdmi, mode);
> } else {
> dev_dbg(hdmi->dev, "%s DVI mode\n", __func__);
> }
> diff --git a/drivers/gpu/drm/bridge/dw-hdmi.h b/drivers/gpu/drm/bridge/dw-hdmi.h
> index 325b0b8..c59f87e 100644
> --- a/drivers/gpu/drm/bridge/dw-hdmi.h
> +++ b/drivers/gpu/drm/bridge/dw-hdmi.h
> @@ -854,6 +854,10 @@ enum {
> HDMI_FC_DBGFORCE_FORCEAUDIO = 0x10,
> HDMI_FC_DBGFORCE_FORCEVIDEO = 0x1,
>
> +/* FC_DATAUTO0 field values */
> + HDMI_FC_DATAUTO0_VSD_MASK = 0x08,
> + HDMI_FC_DATAUTO0_VSD_OFFSET = 3,
> +
> /* PHY_CONF0 field values */
> HDMI_PHY_CONF0_PDZ_MASK = 0x80,
> HDMI_PHY_CONF0_PDZ_OFFSET = 7,