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

[Dmitry Osipenko]

08.01.2020 14:37, Jon Hunter пишет:
> 
> 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 chatted with Sameer about this, so yes the AHUB can repack, but there
> is a problem with S24_LE where if we try to extract 24-bits we actually
> get the upper 24-bits and not the lower LSBs in the 32-bit data element.
> So actually we don't support S24_LE.
> 
> Ben do you need 24-bit support or 32-bit or both?

Any updates? Should we revert all the applied patches for now?