From: "arnaud.mouiche@invoxia.com" <arnaud.mouiche@invoxia.com>
To: Caleb Crome <caleb@crome.org>
Cc: "alsa-devel@alsa-project.org" <alsa-devel@alsa-project.org>
Subject: Re: Multiple codecs on one sound card for multi-channel sound card
Date: Thu, 17 Sep 2015 16:33:29 +0200 [thread overview]
Message-ID: <55FACF39.4010506@invoxia.com> (raw)
In-Reply-To: <CAG5mAdzOhq2_P7fyHrr3JoLoTEjrn2zTmGDti_cdChiXAt6p7w@mail.gmail.com>
hello,
Le 17/09/2015 15:38, Caleb Crome a écrit :
> On Thu, Sep 17, 2015 at 1:51 AM, arnaud.mouiche@invoxia.com
> <arnaud.mouiche@invoxia.com> wrote:
>> Hello Caleb,
>>
>> freescale SSI is fine with more than 2 channels.
>> I have planed to publish a set of patch in this direction but we still have
>> some corner cases to fix first (rare issues with channels alignment)
>>
> I'd love to see anything you're willing to show :-)
>
>> Yet, this following is far enough to have it working.
>> And since the max/min rate is at the end the intersection of what the SSI,
>> the codec and the card are declaring, it will not change anything until you
>> connect the SSI to a codec with more than 2 channels, or a multi-codec
>> solution.
> What if I change channels_max to 16 for capture and playback? Last
> time I tried, it would not keep the channels synchronized on the TDM
> bus. I tried playing with the FIFO settings, which helped, but it
> still would not start each channel in the right slot reliably.
> Perhaps I was using an older kernel.
you put the finger on what's hurting ! ;)
In fact, we made 8 channels working in reliable way on imx50, with
predictive latency ... with an old kernel (3.17) ... based on freescale
BSP... on sound/soc/imx/imx-ssi.c (something that doesn't exist outside
freescale BSP)
Well, just to say it is doable on any recent imx since the hardware is
not the issue. But the job was a set of awful hacks.
My plan was to re-do all this job on an upstream kernel, in a way it can
be accepted.
Unfortunately you will have to wait, I'm under pressure for other stuff
right now.
Regards,
arnaud
>
> I'll give it a try again. Like I said, we'd love to get our
> 16-channel board up and running on the MX6, so I'm definitely
> motivated to put some work in to get it reliable.
>
> Thanks,
> -Caleb
>
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next prev parent reply other threads:[~2015-09-17 14:33 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-09 1:02 Multiple codecs on one sound card for multi-channel sound card Caleb Crome
2015-09-10 18:26 ` Caleb Crome
2015-09-15 1:07 ` Caleb Crome
2015-09-16 9:57 ` arnaud.mouiche
2015-09-16 22:07 ` Caleb Crome
2015-09-17 8:51 ` arnaud.mouiche
2015-09-17 13:38 ` Caleb Crome
2015-09-17 14:33 ` arnaud.mouiche [this message]
2015-09-17 15:34 ` Caleb Crome
2015-09-17 16:09 ` arnaud.mouiche
2015-09-17 17:39 ` Caleb Crome
-- strict thread matches above, loose matches on Subject: below --
2019-02-12 10:55 Yann CARDAILLAC
2019-02-18 8:32 ` Arnaud Mouiche
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