3.16.7-ckt14 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Lukas Wunner <lukas@xxxxxxxxx> 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 <lukas@xxxxxxxxx> Tested-by: Lukas Wunner <lukas@xxxxxxxxx> Reviewed-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> [Jani: included spec reference into the commit message] Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx> Cc: Kamal Mostafa <kamal@xxxxxxxxxxxxx> [ luis: backported to 3.16: adjusted context ] Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx> --- 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 e61b29cb2d29..2ec2d77e3393 100644 --- a/drivers/gpu/drm/i915/intel_lvds.c +++ b/drivers/gpu/drm/i915/intel_lvds.c @@ -854,6 +854,11 @@ 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; @@ -1111,6 +1116,8 @@ 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"); @@ -1122,7 +1129,6 @@ out: } drm_sysfs_connector_add(connector); - intel_panel_init(&intel_connector->panel, fixed_mode, downclock_mode); intel_panel_setup_backlight(connector); return; -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html