[alsa-devel] [PATCH V2 5/7] ALSA: x86: hdmi: Improve position reporting

[Pierre-Louis Bossart]

On 1/6/17 7:21 PM, Jerome Anand wrote:
> Use a hw register to calculate sub-period position reports.
> This makes PulseAudio happier.

 From Takashi: There is no big merit to keep this a separate patch.
Please fold into the main patch. You can put some comment in the code 
for explanation.



>
> Signed-off-by: David Henningsson <david.henningsson at canonical.com>
> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
> Signed-off-by: Jerome Anand <jerome.anand at intel.com>
> ---
>  sound/x86/intel_hdmi_audio.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/sound/x86/intel_hdmi_audio.c b/sound/x86/intel_hdmi_audio.c
> index d7b57658..d2036bc 100644
> --- a/sound/x86/intel_hdmi_audio.c
> +++ b/sound/x86/intel_hdmi_audio.c
> @@ -1489,6 +1489,8 @@ static snd_pcm_uframes_t snd_intelhad_pcm_pointer(
>  {
>  	struct snd_intelhad *intelhaddata;
>  	u32 bytes_rendered = 0;
> +	u32 t;
> +	int buf_id;
>
>  	/* pr_debug("snd_intelhad_pcm_pointer called\n"); */
>
> @@ -1499,6 +1501,14 @@ static snd_pcm_uframes_t snd_intelhad_pcm_pointer(
>  		return SNDRV_PCM_POS_XRUN;
>  	}
>
> +	buf_id = intelhaddata->curr_buf % 4;
> +	had_read_register(AUD_BUF_A_LENGTH + (buf_id * HAD_REG_WIDTH), &t);
> +	if (t == 0) {
> +		pr_debug("discovered buffer done for buf %d\n", buf_id);
> +		/* had_process_buffer_done(intelhaddata); */
> +	}
> +	t = intelhaddata->buf_info[buf_id].buf_size - t;
> +
>  	if (intelhaddata->stream_info.buffer_rendered)
>  		div_u64_rem(intelhaddata->stream_info.buffer_rendered,
>  			intelhaddata->stream_info.ring_buf_size,
> @@ -1506,7 +1516,7 @@ static snd_pcm_uframes_t snd_intelhad_pcm_pointer(
>
>  	intelhaddata->stream_info.buffer_ptr = bytes_to_frames(
>  						substream->runtime,
> -						bytes_rendered);
> +						bytes_rendered + t);
>  	return intelhaddata->stream_info.buffer_ptr;
>  }
>
>