On Mon, Nov 16, 2009 at 06:14:14PM +0100, Takashi Iwai 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@xxxxxxxxx> > > > Signed-off-by: Wu Zhangjin <wuzj@xxxxxxxxxx> > > > > 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 ... > > Indeed. My preference option is to deploy dma_mmap_coherent() to > possible architectures and use it commonly in the ALSA core code. > > But, as a temporary workaround, I'm fine with ifdef until the API is > defined... There is a MIPS platform which may be based on a variety of system controllers only one of which supports cache coherency. So we want to deciede at runtime not at compile time. Ralf
