[Gnewsense-dev] Re: Fixup of the ALSA output of linux-2.6.33 for loongson

[Wu Zhangjin]

(put Karl Goetz, gnewsense-dev into the CC: list.)

On Tue, 2010-04-13 at 10:39 +0800, Wu Zhangjin wrote:
> Hi, 
> 
> Heihaier have reported that the ALSA output of linux 2.6.33 for Loongson
> is broken, I have checked it, it was really broken:
> 
> This works well (with OSS output)
> 
> $ mplayer -ao oss file.mp3
> 
> This is broken (with ALSA output)
> 
> $ mplayer -ao alsa file.mp3
> 
> To fix this problem, a patch[1] for MIPS from the ALSA maintainer is
> applied into the latest linux-loongson/2.6.33/stable of the rt4ls git
> repo and the master branch of linux-loongson/community.
> 
> If you are using the old linux-2.6.33 and need a good ALSA output
> support, please use the latest linux-loongson/2.6.33/stable branch of
> rt4ls git repo or apply [1] yourself,

That patch [1] can not be applied into the linux-loongson/2.6.33/stable
directly, you need to apply this one:

http://dev.lemote.com/cgit/rt4ls.git/commit/?h=linux-loongson/2.6.33/stable&id=de7c960a9cf8c93fa3b2c4505a6e89194163bcbb

>  thanks!
> 
> BTW: before, we have applied the old patch[2] to fix the ALSA problem,

'Before' above means for the linux kernel <= 2.6.32, so, please don't
try to apply [1] to the old linux kernel for loongson, but the old
patch[2] for there are some changes from the mainline 2.6.33.

> but the better method is implementing the MIPS specific
> dma_mmap_coherent(), however, since the dma_mmap_coherent() from [1] is
> not suitable to all of the MIPS variants, Ralf have not applied that
> patch yet, therefore, we need to apply it ourselves.
> 
> Thanks to heihaier!
> 
> Regards,
>       Wu Zhangjin
> 
> -------------
> [1] http://www.linux-mips.org/archives/linux-mips/2008-08/msg00178.html
> [2] http://www.linux-mips.org/archives/linux-mips/2009-05/msg00305.html