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@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>

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index a74aaf9242b965797114c0d775171b181ffdd423..88b36a9173c98d0ea97b7e5423e570c10b29ad5b 100644 (file)
--- 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_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,
@@ -2026,8 +2026,8 @@ 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)