diff options
| author | Jani Nikula <jani.nikula@intel.com> | 2014-05-14 10:02:19 (GMT) |
|---|---|---|
| committer | Jani Nikula <jani.nikula@intel.com> | 2014-05-15 08:04:21 (GMT) |
| commit | f4cdbc21444a45d207a8dc175f44d2facfbd0845 (patch) | |
| tree | 6dce3dadce11603c059d17a2dc9ac5360b1dce87 | |
| parent | 05adaf1f101f25f40f12c29403e6488f0e45f6b6 (diff) | |
| download | linux-f4cdbc21444a45d207a8dc175f44d2facfbd0845.tar.xz | |
drm/i915/dp: force eDP lane count to max available lanes on BDW
There are certain BDW high res eDP machines that regressed due to
commit 38aecea0ccbb909d635619cba22f1891e589b434
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Mon Mar 3 11:18:10 2014 +0100
drm/i915: reverse dp link param selection, prefer fast over wide again
The commit lead to 2 lanes at 5.4 Gbps being used instead of 4 lanes at
2.7 Gbps on the affected machines. Link training succeeded for both, but
the screen remained blank with the former config. Further investigation
showed that 4 lanes at 5.4 Gbps worked also.
The root cause for the blank screen using 2 lanes remains unknown, but
apparently the driver for a certain other operating system by default
uses the max available lanes. Follow suit on Broadwell eDP, for at least
until we figure out what is going on.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=76711
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Tested-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
| -rw-r--r-- | drivers/gpu/drm/i915/intel_dp.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 8233f2a..2a00cb8 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -810,7 +810,12 @@ intel_dp_compute_config(struct intel_encoder *encoder, bpp = dev_priv->vbt.edp_bpp; } - if (dev_priv->vbt.edp_lanes) { + if (IS_BROADWELL(dev)) { + /* Yes, it's an ugly hack. */ + min_lane_count = max_lane_count; + DRM_DEBUG_KMS("forcing lane count to max (%u) on BDW\n", + min_lane_count); + } else if (dev_priv->vbt.edp_lanes) { min_lane_count = min(dev_priv->vbt.edp_lanes, max_lane_count); DRM_DEBUG_KMS("using min %u lanes per VBT\n", |