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From: Ralf Baechle <ralf@linux-mips.org>
To: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: geert@linux-m68k.org, jsun@mvista.com, linux-mips@linux-mips.org
Subject: Re: semaphore woes in 2.6, 32bit
Date: Mon, 10 May 2004 16:06:06 +0200	[thread overview]
Message-ID: <20040510140606.GA9312@linux-mips.org> (raw)
In-Reply-To: <20040510.222845.78701815.anemo@mba.ocn.ne.jp>

On Mon, May 10, 2004 at 10:28:45PM +0900, Atsushi Nemoto wrote:

> >> Hmm, many drivers use kmalloc and pci_map_single for DMA buffer.
> >> So ARCH_KMALLOC_MINALIGN should be L1_CACHE_BYTES for non-coherent
> >> system?
> 
> ralf> No, those drivers are simply broken.  dma_get_cache_alignment()
> ralf> gives the mimimum alignment and width for DMA mappings and that
> ralf> value is larger than kmalloc alignment in almost all cases.
> 
> I see.  Thank you for pointing out it.  I must learn 2.6 DMA API
> quickly ...

This also applies to the 2.4 PCI DMA API.

  Ralf

  reply	other threads:[~2004-05-10 14:06 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-05-08  1:10 semaphore woes in 2.6, 32bit Jun Sun
2004-05-08  7:18 ` Ralf Baechle
2004-05-09  5:48   ` Jun Sun
2004-05-09  9:09     ` Geert Uytterhoeven
2004-05-09 12:57       ` Ralf Baechle
2004-05-09 13:56         ` Atsushi Nemoto
2004-05-09 16:48           ` Ralf Baechle
2004-05-10 13:28             ` Atsushi Nemoto
2004-05-10 14:06               ` Ralf Baechle [this message]
2004-05-11 13:53                 ` Atsushi Nemoto
2004-05-11 14:05                   ` Ralf Baechle

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