Patch "drm/i915: Fix eDP low vswing for Broadwell" has been added to the 4.5-stable tree

Patch "drm/i915: Fix eDP low vswing for Broadwell" has been added to the 4.5-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    drm/i915: Fix eDP low vswing for Broadwell

to the 4.5-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-i915-fix-edp-low-vswing-for-broadwell.patch
and it can be found in the queue-4.5 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 992e7a41f9fcc7bcd10e7d346aee5ed7a2c241cb Mon Sep 17 00:00:00 2001
From: Mika Kahola <mika.kahola@intel.com>
Date: Wed, 20 Apr 2016 15:39:02 +0300
Subject: drm/i915: Fix eDP low vswing for Broadwell
MIME-Version: 1.0
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From: Mika Kahola <mika.kahola@intel.com>

commit 992e7a41f9fcc7bcd10e7d346aee5ed7a2c241cb upstream.

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
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
(cherry picked from commit 00983519214b61c1b9371ec2ed55a4dde773e384)
[Jani: s/dev_priv->vbt.edp.low_vswing/dev_priv->edp_low_vswing/ to backport]
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/i915/intel_ddi.c |   12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -464,9 +464,17 @@ static void intel_prepare_ddi_buffers(st
 	} else if (IS_BROADWELL(dev)) {
 		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;


Patches currently in stable-queue which might be from mika.kahola@intel.com are

queue-4.5/drm-i915-fix-edp-low-vswing-for-broadwell.patch