From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Apparently some sinks look at the YQ bits even when receiving RGB,
and they get somehow confused when they see a non-zero YQ value.
So we can't just blindly follow CEA-861-F and set YQ to match the
RGB range.
Unfortunately there is no good way to tell whether the sink
designer claims to have read CEA-861-F. The CEA extension block
revision number has generally been stuck at 3 since forever,
and even a very recently manufactured sink might be based on
an old design so the manufacturing date doesn't seem like
something we can use. In lieu of better information let's
follow CEA-861-F only for HDMI 2.0 sinks, since HDMI 2.0 is
based on CEA-861-F. For HDMI 1.x sinks we'll always set YQ=0.
The alternative would of course be to always set YQ=0. And if
we ever encounter a HDMI 2.0+ sink with this bug that's what
we'll probably have to do.
Cc: stable@xxxxxxxxxxxxxxx
Cc: Jani Nikula <jani.nikula@xxxxxxxxx>
Cc: Eric Anholt <eric@xxxxxxxxxx>
Cc: Neil Kownacki <njkkow@xxxxxxxxx>
Reported-by: Neil Kownacki <njkkow@xxxxxxxxx>
Fixes: fcc8a22cc905 ("drm/edid: Set YQ bits in the AVI infoframe according to CEA-861-F")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=101639
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/drm_edid.c | 12 ++++++++++--
drivers/gpu/drm/i915/intel_hdmi.c | 3 ++-
drivers/gpu/drm/vc4/vc4_hdmi.c | 3 ++-
include/drm/drm_edid.h | 3 ++-
4 files changed, 16 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 749d07a01772..8567890f47a7 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -4838,7 +4838,8 @@ void
drm_hdmi_avi_infoframe_quant_range(struct hdmi_avi_infoframe *frame,
const struct drm_display_mode *mode,
enum hdmi_quantization_range rgb_quant_range,
- bool rgb_quant_range_selectable)
+ bool rgb_quant_range_selectable,
+ bool is_hdmi2_sink)
{
/*
* CEA-861:
@@ -4862,8 +4863,15 @@ drm_hdmi_avi_infoframe_quant_range(struct hdmi_avi_infoframe *frame,
* YQ-field to match the RGB Quantization Range being transmitted
* (e.g., when Limited Range RGB, set YQ=0 or when Full Range RGB,
* set YQ=1) and the Sink shall ignore the YQ-field."
+ *
+ * Unfortunate certain sinks (eg. VIZ Model 67/E261VA) get confused
+ * by non-zero YQ when receiving RGB. There doesn't seem to be any
+ * good way to tell which version of CEA-861 the sink supports, so
+ * we limit non-zero YQ to HDMI 2.0 sinks only as HDMI 2.0 is based
+ * on on CEA-861-F.
*/
- if (rgb_quant_range == HDMI_QUANTIZATION_RANGE_LIMITED)
+ if (!is_hdmi2_sink ||
+ rgb_quant_range == HDMI_QUANTIZATION_RANGE_LIMITED)
frame->ycc_quantization_range =
HDMI_YCC_QUANTIZATION_RANGE_LIMITED;
else
diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index fa1c793a21ef..2b23d3662eec 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -487,7 +487,8 @@ static void intel_hdmi_set_avi_infoframe(struct drm_encoder *encoder,
crtc_state->limited_color_range ?
HDMI_QUANTIZATION_RANGE_LIMITED :
HDMI_QUANTIZATION_RANGE_FULL,
- intel_hdmi->rgb_quant_range_selectable);
+ intel_hdmi->rgb_quant_range_selectable,
+ is_hdmi2_sink);
/* TODO: handle pixel repetition for YCBCR420 outputs */
intel_write_infoframe(encoder, crtc_state, &frame);
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 9a9a6b4acccf..d645df0c6d15 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -423,7 +423,8 @@ static void vc4_hdmi_set_avi_infoframe(struct drm_encoder *encoder)
vc4_encoder->limited_rgb_range ?
HDMI_QUANTIZATION_RANGE_LIMITED :
HDMI_QUANTIZATION_RANGE_FULL,
- vc4_encoder->rgb_range_selectable);
+ vc4_encoder->rgb_range_selectable,
+ false);
vc4_hdmi_write_infoframe(encoder, &frame);
}
diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
index 9e4e23524840..58ffb68efdc5 100644
--- a/include/drm/drm_edid.h
+++ b/include/drm/drm_edid.h
@@ -361,7 +361,8 @@ void
drm_hdmi_avi_infoframe_quant_range(struct hdmi_avi_infoframe *frame,
const struct drm_display_mode *mode,
enum hdmi_quantization_range rgb_quant_range,
- bool rgb_quant_range_selectable);
+ bool rgb_quant_range_selectable,
+ bool is_hdmi2_sink);
/**
* drm_eld_mnl - Get ELD monitor name length in bytes.
--
2.13.6