[PATCH v2] drm/display: add hw_params callback function to drm_connector_hdmi_audio_ops

From: Jianfeng Liu
Date: Thu Sep 25 2025 - 00:06:02 EST


After reusing drm_hdmi_audio_* helpers and drm_bridge_connector
integration in drm/msm/dp, we have dropped msm_dp_audio_hw_params and
use msm_dp_audio_prepare instead. While userspace is still calling
hw_params to do audio initialization, and we get the following errors:

q6apm-lpass-dais 3700000.remoteproc:glink-edge:gpr:service@1:bedais: q6apm_lpass_dai_prepare() started
q6apm-lpass-dais 3700000.remoteproc:glink-edge:gpr:service@1:bedais: q6apm_lpass_dai_prepare() started
q6apm-lpass-dais 3700000.remoteproc:glink-edge:gpr:service@1:bedais: q6apm_lpass_dai_prepare() started
hdmi-audio-codec hdmi-audio-codec.0.auto: hdmi_codec_hw_params() started
q6apm-lpass-dais 3700000.remoteproc:glink-edge:gpr:service@1:bedais: q6apm_lpass_dai_prepare() started
qcom-apm gprsvc:service:2:1: Error (1) Processing 0x01001002 cmd
qcom-apm gprsvc:service:2:1: DSP returned error[1001002] 1
q6apm-lpass-dais 3700000.remoteproc:glink-edge:gpr:service@1:bedais: Failed to start APM port 104
q6apm-lpass-dais 3700000.remoteproc:glink-edge:gpr:service@1:bedais: ASoC error (-22): at snd_soc_dai_prepare() on DISPLAY_PORT_RX_0
MultiMedia2 Playback: ASoC error (-22): at dpcm_run_update_startup() on MultiMedia2 Playback

msm_dp_audio_prepare is not called because hdmi-codec driver only checks
and runs hw_params before q6apm_lpass_dai_prepare(). This commit will
add hw_params callback same as drm_connector_hdmi_audio_prepare, so that
hdmi-codec driver can work with userspace alsa.

Tested with Radxa Dragon Q6A.

Fixes: 98a8920e7b07 ("drm/msm/dp: reuse generic HDMI codec implementation")
Signed-off-by: Jianfeng Liu <liujianfeng1994@xxxxxxxxx>
---

Changes in v2:
- Link to v1: https://lore.kernel.org/linux-arm-msm/20250924085804.34183-1-liujianfeng1994@xxxxxxxxx/
- Use more detailed trace log in commit message.
- Drop the empty line between Fixex and SoB.

drivers/gpu/drm/display/drm_hdmi_audio_helper.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/display/drm_hdmi_audio_helper.c b/drivers/gpu/drm/display/drm_hdmi_audio_helper.c
index 7d78b02c1446..6ca1c7ad0632 100644
--- a/drivers/gpu/drm/display/drm_hdmi_audio_helper.c
+++ b/drivers/gpu/drm/display/drm_hdmi_audio_helper.c
@@ -130,6 +130,7 @@ EXPORT_SYMBOL(drm_connector_hdmi_audio_plugged_notify);

static const struct hdmi_codec_ops drm_connector_hdmi_audio_ops = {
.audio_startup = drm_connector_hdmi_audio_startup,
+ .hw_params = drm_connector_hdmi_audio_prepare,
.prepare = drm_connector_hdmi_audio_prepare,
.audio_shutdown = drm_connector_hdmi_audio_shutdown,
.mute_stream = drm_connector_hdmi_audio_mute_stream,
--
2.43.0