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

[Jon Hunter]

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

-- 
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