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

[Jani Nikula]

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 warnings.

Fix this by not enabling audio on port A on non-DDI platforms. The check
could be made more specific, but this corresponds to the audio codec
enabling code which emits the warning for port A.

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 | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 937ba31d8dde..fa71fb4d6542 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1355,7 +1355,8 @@ 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;
+	if (HAS_DDI(dev) || port != PORT_A)
+		pipe_config->has_audio = intel_dp->has_audio;
 
 	if (is_edp(intel_dp) && intel_connector->panel.fixed_mode) {
 		intel_fixed_panel_mode(intel_connector->panel.fixed_mode,
@@ -2228,7 +2229,7 @@ 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)
+	if (port != PORT_A && tmp & DP_AUDIO_OUTPUT_ENABLE)
 		pipe_config->has_audio = true;
 
 	if ((port == PORT_A) || !HAS_PCH_CPT(dev)) {
-- 
2.1.4