From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754495AbbEZP5j (ORCPT ); Tue, 26 May 2015 11:57:39 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:34049 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754261AbbEZPmp (ORCPT ); Tue, 26 May 2015 11:42:45 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Lukas Wunner , Jani Nikula , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 60/92] drm/i915: Assume dual channel LVDS if pixel clock necessitates it Date: Tue, 26 May 2015 08:41:04 -0700 Message-Id: <1432654896-28478-61-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1432654896-28478-1-git-send-email-kamal@canonical.com> References: <1432654896-28478-1-git-send-email-kamal@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.19.8-ckt1 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Lukas Wunner commit 6f317cfe42c9d8a7c9c1a327d2f1bcc517a3cd91 upstream. Single channel LVDS maxes out at 112 MHz, anything above must be dual channel. This avoids the need to specify i915.lvds_channel_mode=2 on all 17" MacBook Pro models with i915 graphics since they had 1920x1200 (193 MHz), plus those 15" pre-retina models which had a resolution of 1680x1050 (119 MHz) as a BTO option. Source for 112 MHz limit of single channel LVDS is section 2.3 of: https://01.org/linuxgraphics/sites/default/files/documentation/ivb_ihd_os_vol3_part4.pdf v2: Avoid hardcoding 17" models by assuming dual channel LVDS if the resolution necessitates it, suggested by Jani Nikula. v3: Fix typo, thanks Joonas Lahtinen. v4: Split commit in two, suggested by Ville Syrjälä. Signed-off-by: Lukas Wunner Tested-by: Lukas Wunner Reviewed-by: Ville Syrjälä [Jani: included spec reference into the commit message] Signed-off-by: Jani Nikula Signed-off-by: Kamal Mostafa --- drivers/gpu/drm/i915/intel_lvds.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c index 14654d6..86bab42 100644 --- a/drivers/gpu/drm/i915/intel_lvds.c +++ b/drivers/gpu/drm/i915/intel_lvds.c @@ -844,6 +844,11 @@ static bool compute_is_dual_link_lvds(struct intel_lvds_encoder *lvds_encoder) if (i915.lvds_channel_mode > 0) return i915.lvds_channel_mode == 2; + /* single channel LVDS is limited to 112 MHz */ + if (lvds_encoder->attached_connector->base.panel.fixed_mode->clock + > 112999) + return true; + if (dmi_check_system(intel_dual_link_lvds)) return true; @@ -1101,6 +1106,8 @@ void intel_lvds_init(struct drm_device *dev) out: mutex_unlock(&dev->mode_config.mutex); + intel_panel_init(&intel_connector->panel, fixed_mode, downclock_mode); + lvds_encoder->is_dual_link = compute_is_dual_link_lvds(lvds_encoder); DRM_DEBUG_KMS("detected %s-link lvds configuration\n", lvds_encoder->is_dual_link ? "dual" : "single"); @@ -1115,7 +1122,6 @@ out: } drm_connector_register(connector); - intel_panel_init(&intel_connector->panel, fixed_mode, downclock_mode); intel_panel_setup_backlight(connector, INVALID_PIPE); return; -- 1.9.1