pcm: dsnoop: Added "hw_ptr_alignment" option in configuration for slave pointer alignment

This change adapt the fix commit 6b058fda9d
("pcm: dmix: Add option to allow alignment of slave pointers")
for dsnoop plugin

Issue is that snd_pcm_wait() goes back to waiting because the hw_ptr
is not period aligned. Therefore snd_pcm_wait() will block for a longer
time as required.

With these rcar driver changes the exact position of the dma is returned.
During snd_pcm_start they read hw_ptr as reference, and this hw_ptr
is now not period aligned, and is a little ahead over the period while it
is read. Therefore when the avail is calculated during snd_pcm_wait(),
it is missing the avail_min by a few frames.

An additional option hw_ptr_alignment is provided to dsnoop configuration,
to allow the user to configure the slave application and hw pointer
alignment at startup

Signed-off-by: Vanitha Channaiah <vanitha.channaiah@in.bosch.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Vanitha Channaiah 2019-05-15 11:56:34 +05:30 committed by Takashi Iwai
parent 7265e603bf
commit 3ab7980047
4 changed files with 33 additions and 2 deletions

View file

@ -2043,7 +2043,6 @@ int snd_pcm_direct_parse_open_conf(snd_config_t *root, snd_config_t *conf,
void snd_pcm_direct_reset_slave_ptr(snd_pcm_t *pcm, snd_pcm_direct_t *dmix)
{
dmix->slave_appl_ptr = dmix->slave_hw_ptr = *dmix->spcm->hw.ptr;
if (dmix->hw_ptr_alignment == SND_PCM_HW_PTR_ALIGNMENT_ROUNDUP ||
(dmix->hw_ptr_alignment == SND_PCM_HW_PTR_ALIGNMENT_AUTO &&