[alsa-devel] [PATCH] MIPS: Fixups of ALSA memory maps

[Ralf Baechle]

On Tue, Nov 17, 2009 at 12:48:14AM +0800, Wu Zhangjin wrote:

> Seems this is MIPS specific, but it's not that easy to move this patch
> into the arch/mips part, So, any better solution?
> 
> Thanks & Regards,
>        Wu Zhangjin
> 
> ------------------------
> 
> The user application mmap audio dma regions must be dma-coherent. This
> patch fix it.
> 
> Without this patch, artsd will fail on boot, and mplayer will exit with
> "Segmentation fault". (this happens on YeeLoong netbook, fuloong2f
> mini pc with snd_cs5535 audio card)
> 
> This is originally from the to-mips branch of
> http://dev.lemote.com/code/linux_loongson, and contributed by Yanhua
> from Lemote Inc.
> 
> Reported-by: qiaochong <qiaochong at gmail.com>
> Signed-off-by: Wu Zhangjin <wuzj at lemote.com>

This issue is an old ghost still around, see:

   http://www.linux-mips.org/cgi-bin/mesg.cgi?a=linux-mips&i=20060124.132832.37533152.nemoto%40toshiba-tops.co.jp

which is a superset of your proposed patch and which itself is refering to
an even older posting from 2003:

   http://www.linux-mips.org/cgi-bin/mesg.cgi?a=linux-mips&i=20030523215935.71373.qmail%40web11901.mail.yahoo.com

The #ifdef'ed solution doesn't cut it for sure.  Let's see what better we
can find ...

  Ralf