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

[Ben Dooks]

On 07/01/2020 10:29, Jon Hunter wrote:
> 
> 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 will check on this. I would have thought that S24_LE (24-bits packed
> into 32-bit elements) would be fine. Typically we don't support S24_3LE
> (24-bits in 24-bit elements).
> 

I've just had to spend time fixing pulseview/sigrok's i2s handling for
this, but have run a simple test of S24_LE using a pattern generator
and the low level output looks ok.

I will test a bit more tomorrow, but I suspect something else is either
getting S24_LE wrong or we have some other issue.


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

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