Patch "drm/i915/dp: there is no audio on port A" has been added to the 4.0-stable tree

[<gregkh@linuxfoundation.org>]

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

    drm/i915/dp: there is no audio on port A

to the 4.0-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-dp-there-is-no-audio-on-port-a.patch
and it can be found in the queue-4.0 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 9fcb1704d1d51b12e2f03c78bca013d0cbbb7c98 Mon Sep 17 00:00:00 2001
From: Jani Nikula <jani.nikula@intel.com>
Date: Tue, 5 May 2015 16:32:12 +0300
Subject: drm/i915/dp: there is no audio on port A

From: Jani Nikula <jani.nikula@intel.com>

commit 9fcb1704d1d51b12e2f03c78bca013d0cbbb7c98 upstream.

The eDP port A register on PCH split platforms has a slightly different
register layout from the other ports, with bit 6 being either alternate
scrambler reset or reserved, depending on the generation. Our
misinterpretation of the bit as audio has lead to warning.

Fix this by not enabling audio on port A, since none of our platforms
support audio on port A anyway.

v2: DDI doesn't have audio on port A either (Sivakumar Thulasimani)

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89958
Reported-and-tested-by: Chris Bainbridge <chris.bainbridge@gmail.com>
Reviewed-by: Sivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/i915/intel_dp.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1176,7 +1176,7 @@ intel_dp_compute_config(struct intel_enc
 
 	pipe_config->has_dp_encoder = true;
 	pipe_config->has_drrs = false;
-	pipe_config->has_audio = intel_dp->has_audio;
+	pipe_config->has_audio = intel_dp->has_audio && port != PORT_A;
 
 	if (is_edp(intel_dp) && intel_connector->panel.fixed_mode) {
 		intel_fixed_panel_mode(intel_connector->panel.fixed_mode,
@@ -2026,8 +2026,8 @@ static void intel_dp_get_config(struct i
 	int dotclock;
 
 	tmp = I915_READ(intel_dp->output_reg);
-	if (tmp & DP_AUDIO_OUTPUT_ENABLE)
-		pipe_config->has_audio = true;
+
+	pipe_config->has_audio = tmp & DP_AUDIO_OUTPUT_ENABLE && port != PORT_A;
 
 	if ((port == PORT_A) || !HAS_PCH_CPT(dev)) {
 		if (tmp & DP_SYNC_HS_HIGH)


Patches currently in stable-queue which might be from jani.nikula@intel.com are

queue-4.0/drm-i915-assume-dual-channel-lvds-if-pixel-clock-necessitates-it.patch
queue-4.0/drm-i915-add-missing-macbook-pro-models-with-dual-channel-lvds.patch
queue-4.0/drm-i915-dp-there-is-no-audio-on-port-a.patch