drm/edid: Allow HDMI infoframe without VIC or S3D

Appedix F of HDMI 2.0 says that some HDMI sink may fail to switch from
3D to 2D mode in a timely fashion if the source simply stops sending the
HDMI infoframe. The suggested workaround is to keep sending the
infoframe even when strictly not necessary (ie. no VIC and no S3D).
HDMI 1.4 does allow for this behaviour, stating that sending the
infoframe is optional in this case.

The infoframe was first specified in HDMI 1.4, so in theory sinks
predating that may not appreciate us sending an uknown infoframe
their way. To avoid regressions let's try to determine if the sink
supports the infoframe or not. Unfortunately there's no direct way
to do that, so instead we'll just check if we managed to parse any
HDMI 1.4 4k or stereo modes from the EDID, and if so we assume the
sink will accept the infoframe. Also if the EDID contains the HDMI
2.0 HDMI Forum VSDB we can assume the sink is prepared to receive
the infoframe.

v2: Fix getting has_hdmi_infoframe from display_info
Always fail constructing the infoframe if the display
possibly can't handle it

Cc: Shashank Sharma <[e-mail]>
Cc: Andrzej Hajda <[e-mail]>
Cc: Laurent Pinchart <[e-mail]>
Signed-off-by: Ville Syrjälä <[e-mail]>
Reviewed-by: Shashank Sharma <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/bridge/sil-sii8620.c

···
 			union hdmi_infoframe frm;
 			u8 mhl_vic[] = { 0, 95, 94, 93, 98 };
 
+			/* FIXME: We need the connector here */
 			drm_hdmi_vendor_infoframe_from_display_mode(
-				&frm.vendor.hdmi, adjusted_mode);
+				&frm.vendor.hdmi, NULL, adjusted_mode);
 			vic = frm.vendor.hdmi.vic;
 			if (vic >= ARRAY_SIZE(mhl_vic))
 				vic = 0;

drivers/gpu/drm/bridge/synopsys/dw-hdmi.c

···
 	u8 buffer[10];
 	ssize_t err;
 
-	err = drm_hdmi_vendor_infoframe_from_display_mode(&frame, mode);
+	err = drm_hdmi_vendor_infoframe_from_display_mode(&frame,
+							  &hdmi->connector,
+							  mode);
 	if (err < 0)
 		/*
 		 * Going into that statement does not means vendor infoframe

drivers/gpu/drm/drm_edid.c

···
 do_hdmi_vsdb_modes(struct drm_connector *connector, const u8 *db, u8 len,
 		   const u8 *video_db, u8 video_len)
 {
+	struct drm_display_info *info = &connector->display_info;
 	int modes = 0, offset = 0, i, multi_present = 0, multi_len;
 	u8 vic_len, hdmi_3d_len = 0;
 	u16 mask;
···
 	}
 
 out:
+	if (modes > 0)
+		info->has_hdmi_infoframe = true;
 	return modes;
 }
 
···
 	struct drm_display_info *display = &connector->display_info;
 	struct drm_hdmi_info *hdmi = &display->hdmi;
 
+	display->has_hdmi_infoframe = true;
+
 	if (hf_vsdb[6] & 0x80) {
 		hdmi->scdc.supported = true;
 		if (hf_vsdb[6] & 0x40)
···
 	info->cea_rev = 0;
 	info->max_tmds_clock = 0;
 	info->dvi_dual = false;
+	info->has_hdmi_infoframe = false;
 
 	if (edid->revision < 3)
 		return;
···
  * drm_hdmi_vendor_infoframe_from_display_mode() - fill an HDMI infoframe with
  * data from a DRM display mode
  * @frame: HDMI vendor infoframe
+ * @connector: the connector
  * @mode: DRM display mode
  *
  * Note that there's is a need to send HDMI vendor infoframes only when using a
···
  */
 int
 drm_hdmi_vendor_infoframe_from_display_mode(struct hdmi_vendor_infoframe *frame,
+					    struct drm_connector *connector,
 					    const struct drm_display_mode *mode)
 {
+	/*
+	 * FIXME: sil-sii8620 doesn't have a connector around when
+	 * we need one, so we have to be prepared for a NULL connector.
+	 */
+	bool has_hdmi_infoframe = connector ?
+		connector->display_info.has_hdmi_infoframe : false;
 	int err;
 	u32 s3d_flags;
 	u8 vic;
···
 	if (!frame || !mode)
 		return -EINVAL;
 
+	if (!has_hdmi_infoframe)
+		return -EINVAL;
+
 	vic = drm_match_hdmi_mode(mode);
 	s3d_flags = mode->flags & DRM_MODE_FLAG_3D_MASK;
 
-	if (!vic && !s3d_flags)
-		return -EINVAL;
+	/*
+	 * Even if it's not absolutely necessary to send the infoframe
+	 * (ie.vic==0 and s3d_struct==0) we will still send it if we
+	 * know that the sink can handle it. This is based on a
+	 * suggestion in HDMI 2.0 Appendix F. Apparently some sinks
+	 * have trouble realizing that they shuld switch from 3D to 2D
+	 * mode if the source simply stops sending the infoframe when
+	 * it wants to switch from 3D to 2D.
+	 */
 
 	if (vic && s3d_flags)
 		return -EINVAL;
···
 	if (err < 0)
 		return err;
 
-	if (vic)
-		frame->vic = vic;
-	else
-		frame->s3d_struct = s3d_structure_from_display_mode(mode);
+	frame->vic = vic;
+	frame->s3d_struct = s3d_structure_from_display_mode(mode);
 
 	return 0;
 }

drivers/gpu/drm/exynos/exynos_hdmi.c

···
 		DRM_INFO("%s: invalid AVI infoframe (%d)\n", __func__, ret);
 	}
 
-	ret = drm_hdmi_vendor_infoframe_from_display_mode(&frm.vendor.hdmi, m);
+	ret = drm_hdmi_vendor_infoframe_from_display_mode(&frm.vendor.hdmi,
+							  &hdata->connector, m);
 	if (!ret)
 		ret = hdmi_vendor_infoframe_pack(&frm.vendor.hdmi, buf,
 				sizeof(buf));

drivers/gpu/drm/i915/intel_hdmi.c

···
 
 static void
 intel_hdmi_set_hdmi_infoframe(struct drm_encoder *encoder,
-			      const struct intel_crtc_state *crtc_state)
+			      const struct intel_crtc_state *crtc_state,
+			      const struct drm_connector_state *conn_state)
 {
 	union hdmi_infoframe frame;
 	int ret;
 
 	ret = drm_hdmi_vendor_infoframe_from_display_mode(&frame.vendor.hdmi,
+							  conn_state->connector,
 							  &crtc_state->base.adjusted_mode);
 	if (ret < 0)
 		return;
···
 
 	intel_hdmi_set_avi_infoframe(encoder, crtc_state);
 	intel_hdmi_set_spd_infoframe(encoder, crtc_state);
-	intel_hdmi_set_hdmi_infoframe(encoder, crtc_state);
+	intel_hdmi_set_hdmi_infoframe(encoder, crtc_state, conn_state);
 }
 
 static bool hdmi_sink_is_deep_color(const struct drm_connector_state *conn_state)
···
 
 	intel_hdmi_set_avi_infoframe(encoder, crtc_state);
 	intel_hdmi_set_spd_infoframe(encoder, crtc_state);
-	intel_hdmi_set_hdmi_infoframe(encoder, crtc_state);
+	intel_hdmi_set_hdmi_infoframe(encoder, crtc_state, conn_state);
 }
 
 static void cpt_set_infoframes(struct drm_encoder *encoder,
···
 
 	intel_hdmi_set_avi_infoframe(encoder, crtc_state);
 	intel_hdmi_set_spd_infoframe(encoder, crtc_state);
-	intel_hdmi_set_hdmi_infoframe(encoder, crtc_state);
+	intel_hdmi_set_hdmi_infoframe(encoder, crtc_state, conn_state);
 }
 
 static void vlv_set_infoframes(struct drm_encoder *encoder,
···
 
 	intel_hdmi_set_avi_infoframe(encoder, crtc_state);
 	intel_hdmi_set_spd_infoframe(encoder, crtc_state);
-	intel_hdmi_set_hdmi_infoframe(encoder, crtc_state);
+	intel_hdmi_set_hdmi_infoframe(encoder, crtc_state, conn_state);
 }
 
 static void hsw_set_infoframes(struct drm_encoder *encoder,
···
 
 	intel_hdmi_set_avi_infoframe(encoder, crtc_state);
 	intel_hdmi_set_spd_infoframe(encoder, crtc_state);
-	intel_hdmi_set_hdmi_infoframe(encoder, crtc_state);
+	intel_hdmi_set_hdmi_infoframe(encoder, crtc_state, conn_state);
 }
 
 void intel_dp_dual_mode_set_tmds_output(struct intel_hdmi *hdmi, bool enable)

drivers/gpu/drm/mediatek/mtk_hdmi.c

···
 	u8 buffer[10];
 	ssize_t err;
 
-	err = drm_hdmi_vendor_infoframe_from_display_mode(&frame, mode);
+	err = drm_hdmi_vendor_infoframe_from_display_mode(&frame,
+							  &hdmi->conn, mode);
 	if (err) {
 		dev_err(hdmi->dev,
 			"Failed to get vendor infoframe from mode: %zd\n", err);

drivers/gpu/drm/nouveau/nv50_display.c

···
 			= hdmi_infoframe_pack(&avi_frame, args.infoframes, 17);
 	}
 
-	ret = drm_hdmi_vendor_infoframe_from_display_mode(&vendor_frame.vendor.hdmi, mode);
+	ret = drm_hdmi_vendor_infoframe_from_display_mode(&vendor_frame.vendor.hdmi,
+							  &nv_connector->base, mode);
 	if (!ret) {
 		/* We have a Vendor InfoFrame, populate it to the display */
 		args.pwr.vendor_infoframe_length

drivers/gpu/drm/rockchip/inno_hdmi.c

···
 	int rc;
 
 	rc = drm_hdmi_vendor_infoframe_from_display_mode(&frame.vendor.hdmi,
+							 &hdmi->connector,
 							 mode);
 
 	return inno_hdmi_upload_frame(hdmi, rc, &frame, INFOFRAME_VSI,

drivers/gpu/drm/sti/sti_hdmi.c

···
 
 	DRM_DEBUG_DRIVER("\n");
 
-	ret = drm_hdmi_vendor_infoframe_from_display_mode(&infoframe, mode);
+	ret = drm_hdmi_vendor_infoframe_from_display_mode(&infoframe,
+							  hdmi->drm_connector,
+							  mode);
 	if (ret < 0) {
 		/*
 		 * Going into that statement does not means vendor infoframe

drivers/gpu/drm/zte/zx_hdmi.c

···
 	int ret;
 
 	ret = drm_hdmi_vendor_infoframe_from_display_mode(&frame.vendor.hdmi,
+							  &hdmi->connector,
 							  mode);
 	if (ret) {
 		DRM_DEV_ERROR(hdmi->dev, "failed to get vendor infoframe: %d\n",

include/drm/drm_connector.h

···
 	bool dvi_dual;
 
 	/**
+	 * @has_hdmi_infoframe: Does the sink support the HDMI infoframe?
+	 */
+	bool has_hdmi_infoframe;
+
+	/**
 	 * @edid_hdmi_dc_modes: Mask of supported hdmi deep color modes. Even
 	 * more stuff redundant with @bus_formats.
 	 */

include/drm/drm_edid.h

···
 					 bool is_hdmi2_sink);
 int
 drm_hdmi_vendor_infoframe_from_display_mode(struct hdmi_vendor_infoframe *frame,
+					    struct drm_connector *connector,
 					    const struct drm_display_mode *mode);
 void
 drm_hdmi_avi_infoframe_quant_range(struct hdmi_avi_infoframe *frame,