From 779c4c2866150c1e5518d703b747f794f91f044c Mon Sep 17 00:00:00 2001 From: Ville Syrjälä Date: Wed, 11 Jan 2017 14:57:24 +0200 Subject: drm/edid: Set AVI infoframe Q even when QS=0 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit HDMI 2.0 recommends that we set the Q bits in the AVI infoframe even when the sink does not support quantization range selection (QS=0). According to CEA-861 we can do that as long as the Q we send matches the default quantization range for the mode. Previously I think I had misread the spec as saying that you can't send a non-zero Q at all when QS=0. But that's not what the spec actually says. v2: Fix typo in commit message (Jani) Signed-off-by: Ville Syrjälä Link: http://patchwork.freedesktop.org/patch/msgid/20170111125725.8086-5-ville.syrjala@linux.intel.com Reviewed-by: Jani Nikula Acked-by: Eric Anholt --- drivers/gpu/drm/drm_edid.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'drivers/gpu/drm/drm_edid.c') diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index bca73a80f156..292cb5023683 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -4296,11 +4296,13 @@ EXPORT_SYMBOL(drm_hdmi_avi_infoframe_from_display_mode); * drm_hdmi_avi_infoframe_quant_range() - fill the HDMI AVI infoframe * quantization range information * @frame: HDMI AVI infoframe + * @mode: DRM display mode * @rgb_quant_range: RGB quantization range (Q) * @rgb_quant_range_selectable: Sink support selectable RGB quantization range (QS) */ 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) { @@ -4310,8 +4312,12 @@ drm_hdmi_avi_infoframe_quant_range(struct hdmi_avi_infoframe *frame, * to the default RGB Quantization Range for the transmitted Picture * unless the Sink indicates support for the Q bit in a Video * Capabilities Data Block." + * + * HDMI 2.0 recommends sending non-zero Q when it does match the + * default RGB quantization range for the mode, even when QS=0. */ - if (rgb_quant_range_selectable) + if (rgb_quant_range_selectable || + rgb_quant_range == drm_default_rgb_quant_range(mode)) frame->quantization_range = rgb_quant_range; else frame->quantization_range = HDMI_QUANTIZATION_RANGE_DEFAULT; -- cgit v1.2.3