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| author | Lukas Wunner <lukas@wunner.de> | 2015-04-12 22:10:35 +0300 |
|---|---|---|
| committer | Jani Nikula <jani.nikula@intel.com> | 2015-05-05 17:09:44 +0300 |
| commit | 6f317cfe42c9d8a7c9c1a327d2f1bcc517a3cd91 (patch) | |
| tree | 37bfafd26944fbe2699eb9344084fd1d94627f04 /drivers/gpu | |
| parent | 5ebe6afaf0057ac3eaeb98defd5456894b446d22 (diff) | |
| download | linux-6f317cfe42c9d8a7c9c1a327d2f1bcc517a3cd91.tar.xz | |
drm/i915: Assume dual channel LVDS if pixel clock necessitates it
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@wunner.de>
Tested-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: stable@vger.kernel.org
[Jani: included spec reference into the commit message]
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_lvds.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c index 5abda1d2c018..ee621e335d04 100644 --- a/drivers/gpu/drm/i915/intel_lvds.c +++ b/drivers/gpu/drm/i915/intel_lvds.c @@ -848,6 +848,11 @@ 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"); @@ -1125,7 +1132,6 @@ out: } drm_connector_register(connector); - intel_panel_init(&intel_connector->panel, fixed_mode, downclock_mode); intel_panel_setup_backlight(connector, INVALID_PIPE); return; |