On Fri, 30 May 2008 02:37:54 -0300 Daniel Ribeiro <[EMAIL PROTECTED]> wrote:
> Daniel Ribeiro wrote:
> > I am not really sure of how the pcap <-> pxa-ssp communication is
> > made, maybe it is 16 bit stereo audio sent with 32bit i2s emulation
> > (8.4.11 of pxa manual) with PXA as slave, maybe it is not... All i know
> > is that it does not work unless we use 32 bit ssp frames for 16 bit
> > audio data.
>
> I did some more research on this and now i am convinced that it is I2S
> MSB with PXA slave.
> The following (untested, its time to sleep ;) ) patches fixes I2S
> emulation on pxa2xx-ssp.c and removes the override hack on ezx.c.
> I think that nobody was using I2S emulation from pxa2xx-ssp.c because
> the hw_params call from soc-core was changing the frame size.
>
> PS: Sorry for the obsolete pxa2xx-ssp version, it shouldnt be hard to
> port the changes for the current version. :)
>
Hi again Daniel,
I talked with Philipp Zabel about your changes, and obviously he said
that this change is way better than my hackish solution but it is not
_right_ yet.
Here are his remarks:
<ao2> hi pH5, we have a proposal from openezx to fix I2S emulation
handling. A central point is to skip frame size mangling in
hw_params when in I2S mode. Here's the patch we are using:
http://svn.openezx.org/branches/kernel-2.6.25.x-patches/asoc-pxa-ssp-i2s.patch
<ao2> it's a bit rough, but at least it gives the idea
<ao2> we are using DAIFMT_MSB (shouldn't it be called DAIFMT_I2S_MSB?)
<pH5> ao2: that isn't universally good either, because on my device
they used TISSP mode, not PSP
<pH5> I guess we need some way to configure this with two different
DAIFMTs
<pH5> also you don't clear SSPSP in i2s emulation mode
anymore, which according to pxa27x docs is needed.
So if we make the changes a bit less intrusive and more general I think
it can be accepted (and there's some hope that pxa2xx-sspc.[ch] can be
in linux-2.6.27).
Regards,
Antonio
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