[alsa-devel] [Linux-kernel] [PATCH v5 2/7] ASoC: tegra: Allow 24bit and 32bit samples

[Jon Hunter]

On 28/01/2020 08:59, Ben Dooks wrote:
> On 27/01/2020 19:23, Dmitry Osipenko wrote:
>> 27.01.2020 22:20, Dmitry Osipenko пишет:
>>> 24.01.2020 19:50, Jon Hunter пишет:
>>>>
>>>> On 23/01/2020 19:38, Ben Dooks wrote:
>>>>> On 07/01/2020 01:39, Dmitry Osipenko wrote:
>>>>>> 06.01.2020 22:00, Ben Dooks пишет:
>>>>>>> On 05/01/2020 10:53, Ben Dooks wrote:
>>>>>>>>
>>>>>>>>
>>>>>>>> On 2020-01-05 01:48, Dmitry Osipenko wrote:
>>>>>>>>> 05.01.2020 03:04, Ben Dooks пишет:
>>>>>>>>>> [snip]
>>>>>>>>>>
>>>>>>>>>> I've just gone through testing.
>>>>>>>>>>
>>>>>>>>>> Some simple data tests show 16 and 32-bits work.
>>>>>>>>>>
>>>>>>>>>> The 24 bit case seems to be weird, it looks like the 24-bit
>>>>>>>>>> expects
>>>>>>>>>> 24 bit samples in 32 bit words. I can't see any packing
>>>>>>>>>> options to
>>>>>>>>>> do 24 bit in 24 bit, so we may have to remove 24 bit sample
>>>>>>>>>> support
>>>>>>>>>> (which is a shame)
>>>>>>>>>>
>>>>>>>>>> My preference is to remove the 24-bit support and keep the 32
>>>>>>>>>> bit in.
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Interesting.. Jon, could you please confirm that 24bit format
>>>>>>>>> isn't
>>>>>>>>> usable on T30?
>>>>>>>>
>>>>>>>> If there is an option of 24 packed into 32, then I think that would
>>>>>>>> work.
>>>>>>>>
>>>>>>>> I can try testing that with raw data on Monday.
>>>>>>>
>>>>>>> I need to check some things, I assumed 24 was 24 packed bits, it
>>>>>>> looks
>>>>>>> like the default is 24 in 32 bits so we may be ok. However I need to
>>>>>>> re-write my test case which assumed it was 24bits in 3 bytes
>>>>>>> (S24_3LE).
>>>>>>>
>>>>>>> I'll follow up later,
>>>>>>
>>>>>> Okay, the S24_3LE isn't supported by RT5640 codec in my case. I
>>>>>> briefly
>>>>>> looked through the TRM doc and got impression that AHUB could re-pack
>>>>>> data stream into something that codec supports, but maybe it's a
>>>>>> wrong
>>>>>> impression.
>>>>>> _________________________________
>>>>>
>>>>> I did a quick test with the following:
>>>>>
>>>>>   sox -n -b 16 -c 2 -r 44100 /tmp/tmp.wav  synth sine 500 vol 0.5
>>>>>   sox -n -b 24 -c 2 -r 44100 /tmp/tmp.wav  synth sine 500 vol 0.5
>>>>>   sox -n -b 32 -c 2 -r 44100 /tmp/tmp.wav  synth sine 500 vol 0.5
>>>>>
>>>>> The 16 and 32 work fine, the 24 is showing a playback output freq
>>>>> of 440Hz instead of 500Hz... this suggests the clock is off, or there
>>>>> is something else weird going on...
>>>>
>>>> I was looking at using sox to create such as file, but the above
>>>> command
>>>> generates a S24_3LE file and not S24_LE file. The codec on Jetson-TK1
>>>> supports S24_LE but does not support S24_3LE and so I cannot test this.
>>>> Anyway, we really need to test S24_LE and not S24_3LE because this is
>>>> the problem that Dmitry is having.
>>>>
>>>> Ben is S24_3LE what you really need to support?
>>>>
>>>> Dmitry, does the following fix your problem?
>>>>
>>>> diff --git a/sound/soc/tegra/tegra30_i2s.c
>>>> b/sound/soc/tegra/tegra30_i2s.c
>>>> index dbed3c5408e7..92845c4b63f4 100644
>>>> --- a/sound/soc/tegra/tegra30_i2s.c
>>>> +++ b/sound/soc/tegra/tegra30_i2s.c
>>>> @@ -140,7 +140,7 @@ static int tegra30_i2s_hw_params(struct
>>>> snd_pcm_substream *substream,
>>>>                  audio_bits = TEGRA30_AUDIOCIF_BITS_16;
>>>>                  sample_size = 16;
>>>>                  break;
>>>> -       case SNDRV_PCM_FORMAT_S24_LE:
>>>> +       case SNDRV_PCM_FORMAT_S24_3LE:
>>>>                  val = TEGRA30_I2S_CTRL_BIT_SIZE_24;
>>>>                  audio_bits = TEGRA30_AUDIOCIF_BITS_24;
>>>>                  sample_size = 24;
>>>> @@ -318,7 +318,7 @@ static const struct snd_soc_dai_driver
>>>> tegra30_i2s_dai_template = {
>>>>                  .channels_max = 2,
>>>>                  .rates = SNDRV_PCM_RATE_8000_96000,
>>>>                  .formats = SNDRV_PCM_FMTBIT_S32_LE |
>>>> -                          SNDRV_PCM_FMTBIT_S24_LE |
>>>> +                          SNDRV_PCM_FMTBIT_S24_3LE |
>>>>                             SNDRV_PCM_FMTBIT_S16_LE,
>>>>          },
>>>>          .capture = {
>>>> @@ -327,7 +327,7 @@ static const struct snd_soc_dai_driver
>>>> tegra30_i2s_dai_template = {
>>>>                  .channels_max = 2,
>>>>                  .rates = SNDRV_PCM_RATE_8000_96000,
>>>>                  .formats = SNDRV_PCM_FMTBIT_S32_LE |
>>>> -                          SNDRV_PCM_FMTBIT_S24_LE |
>>>> +                          SNDRV_PCM_FMTBIT_S24_3LE |
>>>>                             SNDRV_PCM_FMTBIT_S16_LE,
>>>>          },
>>>>          .ops = &tegra30_i2s_dai_ops,
>>>>
>>>> Jon
>>>>
>>>
>>> It should solve the problem in my particular case, but I'm not sure that
>>> the solution is correct.
>>>
>>> The v5.5 kernel is released now with the broken audio and apparently
>>> getting 24bit to work won't be trivial (if possible at all). Ben, could
>>> you please send a patch to fix v5.5 by removing the S24 support
>>> advertisement from the driver?
>>
>> I also suspect that s32 may need some extra patches and thus could be
>> worthwhile to stop advertising it as well.
> 
> As far as I am aware that works and we can hit the audio rates for it.

I ran a test on Tegra124 Jetson-TK1 and 24-bit playback seems to work as
Ben has indicated. So I don't think it is broken.

Can you try Ben's testcase on Tegra30 (ie. generate a tone using sox and
use aplay to play)?

Jon

-- 
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