Re: [alsa-devel] [PATCH v4 05/14] ASoC: hdac_hdmi: Apply constraints based on ELD

On Wed, Dec 09, 2015 at 09:46:12PM +0530, Subhransu S. Prusty wrote:

+static int hdac_hdmi_eld_limit_formats(struct snd_pcm_runtime *runtime,

• 				void *eld)
  

+{

• u64 formats = SNDRV_PCM_FMTBIT_S16;
• int i;
• const u8 *sad, *eld_buf = eld;
• sad = drm_eld_sad(eld_buf);
• if (!sad)

• goto format_constraint;
  

• for (i = drm_eld_sad_count(eld_buf); i > 0; i--, sad += 3) {

• if (sad_format(sad) == 1) { /* AUDIO_CODING_TYPE_LPCM */
  

switch (sad_format(sad)) { case AUDIO_CODING_TYPE_LPCM:

• 	/* 20 bit and 24 bit */
  

• 	if (sad_sample_bits_lpcm(sad) & 0x6)
  

• 		formats |= SNDRV_PCM_FMTBIT_S32;
  

• }
  

• }

I really don't have a clear idea what the above is supposed to do or why this is specific to HDAC and not handled...

• return 0;

• return snd_pcm_hw_constraint_eld(substream->runtime,

• 		dai_map->pin->eld.eld_buffer);
  

...here.