On Fri, Sep 26, 2025 at 11:30:26AM +0100, Srinivas Kandagatla wrote:
>
>
> On 9/25/25 5:28 AM, Dmitry Baryshkov wrote:
> > On Thu, Sep 25, 2025 at 12:05:09PM +0800, Jianfeng Liu wrote:
> >> 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
> >
> > And a call to hdmi_codec_prepare() comes only at this place.
> >
> > Srini, Mark, when selecting to only implement .prepare for codec ops I
> > was following the commit 2fef64eec23a ("ASoC: hdmi-codec: Add a prepare
> > hook"), which documents that IEC958 status bit is set after
> > .hw_params(), so it's only visible during .prepare(). Is it okay to
> > implement both callbacks? Or should the audioreach DAI driver be fixed
> > somehow instead (I suppose it assumes that the port is available after
> > .hw_params(), not sure if that assumption is correct)?
> >
> >>
> >> 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 <[email protected]>
> >
> > The patch LGTM, but I would wait for response from audio maintainers.
> >
>
> The ordering matters in this case as we need clocks and audio
> configuration on DP codec side to be setup before we start configuring
> the dsp pipeline. Looks like that DSP is trying to setup DP endpoint
> even before it is ready.
>
> q6apm prepare loads the dsp pipeline and starts configuring the
> endpoints, if the DP endpoint is not ready dsp would throw an error.
>
> We might be able to pull in some dsp logs to confirm this, but I dont
> have a setup that I can reproduce this issue.
What would be your recommendation to proceed? Is it okay for the DAI
driver to depend on the .hw_params enabling the clock? Also I see that
the error regarding the clocks comes from .prepare callback too. What is
the order of .prepare callbacks()? Can we influence it?
>
>
> --srini
> >> ---
> >>
> >> Changes in v2:
> >> - Link to v1:
> >> https://lore.kernel.org/linux-arm-msm/[email protected]/
> >> - 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
> >>
> >
>
--
With best wishes
Dmitry
