From e1d44f9829e94a4cad713cc2aefe7b43dfdc328d Mon Sep 17 00:00:00 2001 From: Jani Nikula Date: Wed, 13 Jan 2016 16:35:20 +0200 Subject: [PATCH] drm/i915/dp: fall back to 18 bpp when sink capability is unknown MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Per DP spec, the source device should fall back to 18 bpp, VESA range RGB when the sink capability is unknown. Fix the color depth clamping. 18 bpp color depth should ensure full color range in automatic mode. The clamping has been HDMI specific since its introduction in commit 5e1e825dc004332159ff77887cecc310ae31e35d Author: Daniel Vetter Date: Fri Apr 19 11:24:34 2013 +0200 drm/i915: Disable high-bpc on pre-1.4 EDID screens Cc: stable@vger.kernel.org Reported-and-tested-by: Dihan Wickremasuriya Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=105331 Reviewed-by: Ville Syrjälä Signed-off-by: Jani Nikula Link: http://patchwork.freedesktop.org/patch/msgid/1452695720-7076-1-git-send-email-jani.nikula@intel.com --- drivers/gpu/drm/i915/intel_display.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index aa24f79d85bfe..68a98570f6582 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -12157,11 +12157,21 @@ connected_sink_compute_bpp(struct intel_connector *connector, pipe_config->pipe_bpp = connector->base.display_info.bpc*3; } - /* Clamp bpp to 8 on screens without EDID 1.4 */ - if (connector->base.display_info.bpc == 0 && bpp > 24) { - DRM_DEBUG_KMS("clamping display bpp (was %d) to default limit of 24\n", - bpp); - pipe_config->pipe_bpp = 24; + /* Clamp bpp to default limit on screens without EDID 1.4 */ + if (connector->base.display_info.bpc == 0) { + int type = connector->base.connector_type; + int clamp_bpp = 24; + + /* Fall back to 18 bpp when DP sink capability is unknown. */ + if (type == DRM_MODE_CONNECTOR_DisplayPort || + type == DRM_MODE_CONNECTOR_eDP) + clamp_bpp = 18; + + if (bpp > clamp_bpp) { + DRM_DEBUG_KMS("clamping display bpp (was %d) to default limit of %d\n", + bpp, clamp_bpp); + pipe_config->pipe_bpp = clamp_bpp; + } } } -- 2.39.5