On 2023-09-12 6:30 PM, Jaroslav Kysela wrote:
On 11. 09. 23 17:45, Cezary Rojewski wrote:
On 2023-09-11 10:43 AM, Cezary Rojewski wrote:
...
Could you help me understand what new code is needed? The
get_subformat() example raised more questions than answers. The patchset
defines snd_pcm_subformat_width(), perhaps you meant that I should
update that function by adding paramter 'format' to its parameters list
and handle it accordingly?
Any guidance would be much appreciated.
What I come up with is a hw_rule for subformat that I add in
snd_pcm_hw_constraints_init(). That piece, plus both STD and MSBITS_MAX
ORed into hw->subformats in snd_pcm_hw_constraints_complete() make
things spin.
static int snd_pcm_hw_rule_subformat(struct snd_pcm_hw_params *params,
struct snd_pcm_hw_rule *rule)
{
struct snd_mask *subformat_mask = hw_param_mask(params,
SNDRV_PCM_HW_PARAM_SUBFORMAT);
struct snd_mask *format_mask = hw_param_mask(params,
SNDRV_PCM_HW_PARAM_FORMAT);
snd_pcm_format_t f;
struct snd_mask m;
int width;
snd_mask_none(&m);
snd_mask_set(&m, SNDRV_PCM_SUBFORMAT_STD);
snd_mask_set(&m, SNDRV_PCM_SUBFORMAT_MSBITS_MAX);
pcm_for_each_format(f) {
if (!snd_mask_test_format(format_mask, f))
continue;
width = snd_pcm_format_width(f);
switch (width) {
case 32:
snd_mask_set(&m, SNDRV_PCM_SUBFORMAT_MSBITS_20);
snd_mask_set(&m, SNDRV_PCM_SUBFORMAT_MSBITS_24);
break;
default:
break;
}
}
return snd_mask_refine(subformat_mask, &m);
}
However, this means snd_hdac_query_supported_pcm() becomes confusing as
you need to MSBITS_MAX regardless of what the codec supports.
After spending additional few hours on this, I'd say I preferred how
things look with MSBITS_32 instead. STD and MSBITS_MAX existing
simultaneously is confusing too.
This is not a correct implementation. Many things are missing including
the proper subformats filter. I sent my own version here for discussion:
https://lore.kernel.org/alsa-devel/20230912162526.7138-1-perex@xxxxxxxx/
I do appreciate the input but I expected that, through guidance, this
patch gets updated. Sending a separate patch, not connected to this
patchset - not even a single reference within the commit message body -
is not nice.
I'd rather send v2 with your patch incorporated as a part of the
patchset. The subformat improvement alone, without showcasing the users
is confusing to the reviewers.
Czarek
