[PATCH 4/9] ASoC: imx: Don't use {en,dis}able_fiq() calls

On Mon, Aug 06, 2012 at 10:41:22PM +0100, Mark Brown wrote:

On Mon, Aug 06, 2012 at 03:39:50PM -0500, Matt Sealey wrote:

quoted

On Mon, Aug 6, 2012 at 3:16 PM, Robert Schwebel

quoted

quoted

That's not true; we still run MX25, MX27, MX35, MX28 on mainline in
active projects.

quoted

I think Shawn Guo (FSL/Linaro) would also disagree, since he's just
posted a large amount of MXS patches to fix up the board for device
trees, and Arnd is pulling them.

MXS != i.MX.

quoted

As far as I know, the FIQ usage is quite valid for the processor it
needs to run on (MX21/27/28, right?) in the modes it runs in (AC97 on
these processors, and maybe MX35 too), and I'm just trying to figure
out what the steps are for

Oh, ick.  What is the problem that means people want to use the FIQ on
these processors?  There's been i.MX2x audio DMA since forever, it had
DMA in mainline before any of the later i.MXs due to them having SDMA.
The original mainline i.MX audio support was done on i.MX27 and didn't
have any issue here, this is the fist I've heard of a problem.

Originally the FIQ support was only used because there hasn't been SDMA
support available at that time.
Nowadays the FIQ support is necessary only for AC97. The AC97 support in
the SSI unit is buggy: It does not allow you to select the slots you
want to receive. At least the wm9712 codec always sends (apart from the
stereo data) data in slot (I think it is) 12. You find this data mixed
in your audio stream. The FIQ driver skips this data to get a valid
audio stream.

One other way to solve this would be to use dma here and to filter out
the data afterwards.

Sascha

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