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

[Fabio Estevam]

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