drm/edid: Don't send non-zero YQ in AVI infoframe for HDMI 1.x sinks

commit 9271c0ca573e02a360b636ecd8cb408852f4e9f6 upstream.

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: Jani Nikula <jani.nikula@intel.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: Neil Kownacki <njkkow@gmail.com>
Reported-by: Neil Kownacki <njkkow@gmail.com>
Tested-by: Neil Kownacki <njkkow@gmail.com>
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@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171108152504.12596-1-ville.syrjala@linux.intel.com
Acked-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 6bb6337be920c6b440ef33f579832368feed86e5..fc7946eb6665c4f07e796ea9c348ffa4c1cc81c8 100644 (file)
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -4809,7 +4809,8 @@ 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:
@@ -4833,8 +4834,15 @@ 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 e8abea7594ec4a5e333162cd1457a0b5f7cf6124..3fed1d3ecdedfdd5b51d13d42924a21d2299fde3 100644 (file)
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -481,7 +481,8 @@ 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 937da8dd65b8b02168aeee602225c8a3e3fa171e..8f71157a2b063b07a3d3c195ae5049a0ddcac03e 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -433,7 +433,8 @@ 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 1e1908a6b1d66eddede740c60ccc5084e2f49deb..a992434ded999d1a6b77cf34dd26a2c0f5a8fbd9 100644 (file)
--- a/include/drm/drm_edid.h
+++ b/include/drm/drm_edid.h
@@ -360,7 +360,8 @@ 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.