@@ -11413,11 +11413,21 @@ 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;
+ }
}
}
This is a note to let you know that I have just added a patch titled drm/i915/dp: fall back to 18 bpp when sink capability is unknown to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-4.2.y-queue This patch is scheduled to be released in version 4.2.8-ckt5. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 4.2.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ---8<------------------------------------------------------------ From 220a6e6f1b668387f46a10e986c531939c1fb043 Mon Sep 17 00:00:00 2001 From: Jani Nikula <jani.nikula@intel.com> Date: Wed, 13 Jan 2016 16:35:20 +0200 Subject: drm/i915/dp: fall back to 18 bpp when sink capability is unknown MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit 5efd407674068dede403551bea3b0b134c32513a upstream. 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 996a2239f93b03c5972923f04b097f65565c5bed Author: Daniel Vetter <daniel.vetter@ffwll.ch> Date: Fri Apr 19 11:24:34 2013 +0200 drm/i915: Disable high-bpc on pre-1.4 EDID screens Reported-and-tested-by: Dihan Wickremasuriya <nayomal@gmail.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=105331 Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Jani Nikula <jani.nikula@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1452695720-7076-1-git-send-email-jani.nikula@intel.com (cherry picked from commit 013dd9e038723bbd2aa67be51847384b75be8253) Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- drivers/gpu/drm/i915/intel_display.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) -- 2.7.0