[PATCH v2] drm/amdgpu: Only enable HDMI audio if display supports it

[Panpan Ren]

From: renpanpan <renpanpan@xxxxxxxxxx>

The amdgpu legacy DCE audio path (dce_v6/v8/v10) unconditionally calls
audio_enable(pin, true) at the end of afmt_setmode(), regardless of
whether the connected display advertises audio support in its EDID.

This causes a phantom HDMI audio output to appear for displays that
have no audio capability (no basic audio bit, no Audio Data Block in
EDID), because the GPU sets the AUDIO_ENABLED register bit, which
drives the HDA codec's ELDV pin sense, making the codec report the
jack as audio-available.

The radeon, nouveau, and dw-hdmi drivers all gate audio enablement on
the display's audio capability. Apply the same check to amdgpu's DCE
afmt_setmode functions, while still respecting the AMDGPU_AUDIO_ENABLE
override for users who explicitly force audio on.

Fixes: e2cdf640cbb5 ("drm/amdgpu: add display controller implementation for si v10")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: renpanpan <renpanpan@xxxxxxxxxx>
---
Changes in v2:
- Respect AMDGPU_AUDIO_ENABLE override for users who force audio on
- Add Fixes tag and Cc: stable@xxxxxxxxxxxxxxx for stable backport

 drivers/gpu/drm/amd/amdgpu/dce_v10_0.c | 6 ++++--
 drivers/gpu/drm/amd/amdgpu/dce_v6_0.c  | 6 ++++--
 drivers/gpu/drm/amd/amdgpu/dce_v8_0.c  | 6 ++++--
 3 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
index f2977fe6d824..69d0c6041d75 100644
--- a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
@@ -1705,8 +1705,10 @@ static void dce_v10_0_afmt_setmode(struct drm_encoder *encoder,
 	WREG32(mmAFMT_RAMP_CONTROL2 + dig->afmt->offset, 0x00000001);
 	WREG32(mmAFMT_RAMP_CONTROL3 + dig->afmt->offset, 0x00000001);
 
-	/* enable audio after to setting up hw */
-	dce_v10_0_audio_enable(adev, dig->afmt->pin, true);
+	/* Only enable audio if the display supports it or is forced on */
+	if (connector->display_info.has_audio ||
+	    to_amdgpu_connector(connector)->audio == AMDGPU_AUDIO_ENABLE)
+		dce_v10_0_audio_enable(adev, dig->afmt->pin, true);
 }
 
 static void dce_v10_0_afmt_enable(struct drm_encoder *encoder, bool enable)
diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
index c68de0fe1d7d..226cfce321ec 100644
--- a/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
@@ -1748,8 +1748,10 @@ static void dce_v6_0_afmt_setmode(struct drm_encoder *encoder,
 		dce_v6_0_audio_dp_enable(encoder, 1);
 	}
 
-	/* enable audio after setting up hw */
-	dce_v6_0_audio_enable(adev, dig->afmt->pin, true);
+	/* Only enable audio if the display supports it or is forced on */
+	if (connector->display_info.has_audio ||
+	    amdgpu_connector->audio == AMDGPU_AUDIO_ENABLE)
+		dce_v6_0_audio_enable(adev, dig->afmt->pin, true);
 }
 
 static void dce_v6_0_afmt_enable(struct drm_encoder *encoder, bool enable)
diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
index c3906270f25e..99f0c5759d75 100644
--- a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
@@ -1653,8 +1653,10 @@ static void dce_v8_0_afmt_setmode(struct drm_encoder *encoder,
 	WREG32(mmAFMT_RAMP_CONTROL2 + offset, 0x00000001);
 	WREG32(mmAFMT_RAMP_CONTROL3 + offset, 0x00000001);
 
-	/* enable audio after setting up hw */
-	dce_v8_0_audio_enable(adev, dig->afmt->pin, true);
+	/* Only enable audio if the display supports it or is forced on */
+	if (connector->display_info.has_audio ||
+	    to_amdgpu_connector(connector)->audio == AMDGPU_AUDIO_ENABLE)
+		dce_v8_0_audio_enable(adev, dig->afmt->pin, true);
 }
 
 static void dce_v8_0_afmt_enable(struct drm_encoder *encoder, bool enable)
-- 
2.43.0