Re: [alsa-devel] [PATCH 06/15] ALSA: pcm: Add DRM helper to set constraint for format

2 Dec 2015

      On Wed, 02 Dec 2015 13:27:21 +0100,
Subhransu S. Prusty wrote:
...
On Tue, Dec 01, 2015 at 01:55:03PM +0100, Takashi Iwai wrote:
...
On Tue, 01 Dec 2015 18:47:02 +0100,
Subhransu S. Prusty wrote:
...
+static int eld_limit_formats(struct snd_pcm_runtime *runtime, void *eld)
+{

u64 formats = SNDRV_PCM_FMTBIT_S16_LE;
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 */

	/* 20 bit */

	if (sad_sample_bits_lpcm(sad) & 0x2)

		formats |= SNDRV_PCM_FMTBIT_S32_LE;

	/* 24 bit */

	if (sad_sample_bits_lpcm(sad) & 0x4)

		formats |= SNDRV_PCM_FMTBIT_S24_LE;

Does it work correctly with HD-audio...?
It works correctly. Do you suspect something wrong?
Traditionally, 24bit is supported by S32 format on HDA controller, so
I wonder it.
Takashi