[alsa-devel] fsl_ssi.c: Getting channel slips with fsl_ssi.c in TDM (network) mode.

[Fabio Estevam]

[Adding Roberto in the thread as he is also trying to get SSI TDM support/

On Tue, Oct 27, 2015 at 2:45 PM, Fabio Estevam <festevam at gmail.com> wrote:
> On Tue, Oct 27, 2015 at 2:42 PM, Caleb Crome <caleb at crome.org> wrote:
>> On Tue, Oct 27, 2015 at 9:10 AM, Fabio Estevam <festevam at gmail.com> wrote:
>>> On Tue, Oct 27, 2015 at 2:02 PM, Caleb Crome <caleb at crome.org> wrote:
>>>
>>>>> Could you please try it without using the external SDMA firmware?
>>>>
>>>> I do need *some* SDMA firmware, correct?  The firmware that I'm using
>>>> ends up in /lib/firmware/imx/sdma/sdma-imx6q.bin and is md5sum
>>>> 5d4584134cc4cba62e1be2f382cd6f3a.
>>>
>>> SSI can operate with the ROM SDMA firmware.
>>>
>>> I would like to know if this issue also happens if you don't pass the
>>> external firmware and use the internal ROM SDMA firmware instead.
>>
>> Ah, good to know.  Do I just remove reference in the .dtsi file?
>> Remove the file from the filesystem?  I'll do both to be doubly sure
>> :-)
>
> Just remove it from the rootfs. Then you will see a message from the
> kernel saying that no external SDMA firmware could be found and that
> the internal one is going to be used.
>
>>> Also, could you try bumping the SSI and SDMA clock rates at the maximum?
>>
>> Any idea how I do that?  I guess it's in the .dtsi file perhaps?  I'll
>> poke around.
>
> You can try to call clk_set_rate() with the maximum allowed frequency
> inside the ssi driver. I don't recall on top of my head what is this
> value though.
>
> Regards,
>
> Fabio Estevam