[3.19.y-ckt stable] Patch "drm/i915/dp: there is no audio on port A" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

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

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.8-ckt1.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 940e70b2677418f32c7a221cbb3b8008bf6fc893 Mon Sep 17 00:00:00 2001
From: Jani Nikula <jani.nikula at intel.com>
Date: Tue, 5 May 2015 16:32:12 +0300
Subject: drm/i915/dp: there is no audio on port A

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 at gmail.com>
Reviewed-by: Sivakumar Thulasimani <sivakumar.thulasimani at intel.com>
Signed-off-by: Jani Nikula <jani.nikula at intel.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/gpu/drm/i915/intel_dp.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 9f6c897..00c8ee9 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1175,7 +1175,7 @@ intel_dp_compute_config(struct intel_encoder *encoder,

 	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,
@@ -2024,8 +2024,8 @@ static void intel_dp_get_config(struct intel_encoder *encoder,
 	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)
--
1.9.1