[Intel-gfx] [PATCH 1/2] drm/i915/dp: there is no audio on port A on non-DDI platforms

[Jani Nikula]

On Tue, 05 May 2015, Sivakumar Thulasimani <sivakumar.thulasimani at intel.com> wrote:
> two points
> 1) The eDP spec says Audio is optional so it is allowed to have audio, 
> but i am yet to come across any eDP panel that supports Audio.
> 2) Also, there is no support for audio in DDI A port as well :)
>
> So please change the check to
>
> if (!is_edp(encoder))

Because the actual limitation we have is "no audio on port A" instead of
"no audio on eDP", I insist we check for port A. Patch below.

BR,
Jani.


>From ca5d2444065ac91db3ad6cfcdbf8a012a4d44556 Mon Sep 17 00:00:00 2001
From: Jani Nikula <jani.nikula at intel.com>
Date: Thu, 9 Apr 2015 12:41:53 +0300
Subject: [PATCH] drm/i915/dp: there is no audio on port A
Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo
Cc: Jani Nikula <jani.nikula at intel.com>

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>
Cc: stable at vger.kernel.org
Signed-off-by: Jani Nikula <jani.nikula at intel.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 caeb6ed99ad2..b61bf9b2f76f 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1361,7 +1361,7 @@ 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,
@@ -2234,8 +2234,8 @@ 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)
-- 
2.1.4


-- 
Jani Nikula, Intel Open Source Technology Center