drm/i915: Fix eDP low vswing for Broadwell

It was noticed on bug #94087 that module parameter
i915.edp_vswing=2 that should override the VBT setting
to use default voltage swing (400 mV) was not applied
for Broadwell.

This patch provides a fix for this by checking if default
i.e. higher voltage swing is requested to be used and
applies the DDI translations table for DP instead of eDP
(low vswing) table.

v2: Combine two if statements into one (Jani)
v3: Change dev_priv->edp_low_vswing to use dev_priv->vbt.edp.low_vswing

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94087
Signed-off-by: Mika Kahola <mika.kahola@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461155942-7749-1-git-send-email-mika.kahola@intel.com
Cc: stable@vger.kernel.org
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
(cherry picked from commit 0098351921)
[Jani: s/dev_priv->vbt.edp.low_vswing/dev_priv->edp_low_vswing/ to backport]
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
This commit is contained in:
Mika Kahola 2016-04-20 15:39:02 +03:00 committed by Jani Nikula
parent 5eaa60c710
commit 992e7a41f9

View File

@ -443,9 +443,17 @@ void intel_prepare_ddi_buffer(struct intel_encoder *encoder)
} else if (IS_BROADWELL(dev_priv)) {
ddi_translations_fdi = bdw_ddi_translations_fdi;
ddi_translations_dp = bdw_ddi_translations_dp;
ddi_translations_edp = bdw_ddi_translations_edp;
if (dev_priv->edp_low_vswing) {
ddi_translations_edp = bdw_ddi_translations_edp;
n_edp_entries = ARRAY_SIZE(bdw_ddi_translations_edp);
} else {
ddi_translations_edp = bdw_ddi_translations_dp;
n_edp_entries = ARRAY_SIZE(bdw_ddi_translations_dp);
}
ddi_translations_hdmi = bdw_ddi_translations_hdmi;
n_edp_entries = ARRAY_SIZE(bdw_ddi_translations_edp);
n_dp_entries = ARRAY_SIZE(bdw_ddi_translations_dp);
n_hdmi_entries = ARRAY_SIZE(bdw_ddi_translations_hdmi);
hdmi_default_entry = 7;