linux-mips
[Top] [All Lists]

Re: ALSA on MIPS platform

To: Takashi Iwai <tiwai@suse.de>
Subject: Re: ALSA on MIPS platform
From: Ralf Baechle <ralf@linux-mips.org>
Date: Wed, 8 Aug 2007 12:58:52 +0100
Cc: Atsushi Nemoto <anemo@mba.ocn.ne.jp>, jiankemeng@gmail.com, tiansm@lemote.com, linux-mips@linux-mips.org, alsa-devel@alsa-project.org, greg@kroah.com
In-reply-to: <s5hlkcnmbll.wl%tiwai@suse.de>
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <46B332AC.8020403@lemote.com> <5861a7880708062253x7133659cm1ff17f451e4f82f8@mail.gmail.com> <5861a7880708062317t21970c81w3f16580858bf50af@mail.gmail.com> <20070807.230157.59463765.anemo@mba.ocn.ne.jp> <20070807175402.GA24731@linux-mips.org> <s5hlkcnmbll.wl%tiwai@suse.de>
Sender: linux-mips-bounce@linux-mips.org
User-agent: Mutt/1.5.14 (2007-02-12)
On Tue, Aug 07, 2007 at 08:41:10PM +0200, Takashi Iwai wrote:

> > It's ALSA that is doing funny things here so there is no point in fixing
> > the arch code to work for ALSA.
> 
> Yep, but OTOH, the arch code doesn't provide a proper standard way to
> mmap the pages allocated via dma_alloc_coherent().  That's the missing
> piece, especially on mips and sparc.  ARM has already one.
> 
> My wish is implementing dma_mmap_coherent() on all architectures, so
> that the driver can use it safely without messy ifdefs.

Adding dma_mmap_coherent has been proposed in 2004 but the discussion for
some reason went nowhere because it apparently isn't implementable on
PARISC due to cache synonyms - on MIPS we'd solve those issues where they
exist by using uncached or writethrough mappings, as apropriate.

  Ralf

<Prev in Thread] Current Thread [Next in Thread>