From patchwork Wed Mar 9 00:27:58 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 594661 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id C07971401B5; Wed, 9 Mar 2016 11:37:20 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1adS7p-0001Em-Rp; Wed, 09 Mar 2016 00:37:17 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1adS2Y-0006qC-E8 for kernel-team@lists.ubuntu.com; Wed, 09 Mar 2016 00:31:50 +0000 Received: from 1.general.kamal.us.vpn ([10.172.68.52] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1adS2Y-0003CG-05; Wed, 09 Mar 2016 00:31:50 +0000 Received: from kamal by fourier with local (Exim 4.86) (envelope-from ) id 1adS2V-0007vc-CK; Tue, 08 Mar 2016 16:31:47 -0800 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 3.19.y-ckt 020/196] drm/i915/dp: fall back to 18 bpp when sink capability is unknown Date: Tue, 8 Mar 2016 16:27:58 -0800 Message-Id: <1457483454-30115-21-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1457483454-30115-1-git-send-email-kamal@canonical.com> References: <1457483454-30115-1-git-send-email-kamal@canonical.com> MIME-Version: 1.0 X-Extended-Stable: 3.19 Cc: Jani Nikula , Kamal Mostafa X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com 3.19.8-ckt16 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Jani Nikula 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 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 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 (cherry picked from commit 013dd9e038723bbd2aa67be51847384b75be8253) Signed-off-by: Kamal Mostafa --- 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 9198724..3aae172 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -9984,11 +9984,21 @@ 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; + } } }