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

[Ben Dooks]

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.


-- 
Ben Dooks				http://www.codethink.co.uk/
Senior Engineer				Codethink - Providing Genius

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