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From: Arnd Bergmann <arnd@arndb.de>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Joerg Roedel <joerg.roedel@amd.com>,
	tom.leiming@gmail.com, fujita.tomonori@lab.ntt.co.jp,
	linux-kernel@vger.kernel.org, akpm@linux-foundation.org
Subject: Re: [PATCH][RFC] asm-generic:remove calling flush_write_buffers() in dma_sync_*_for_cpu
Date: Tue, 30 Jun 2009 15:38:43 +0200	[thread overview]
Message-ID: <200906301538.44684.arnd@arndb.de> (raw)
In-Reply-To: <20090630140945.0784e174@lxorguk.ukuu.org.uk>

On Tuesday 30 June 2009, Alan Cox wrote:
> > > What about non x86 - this is asm-generic you are playing with and its the
> > > kind of change that causes evil really hard to track down and subtle
> > > corruptions and user data loss if you get it wrong.
> > 
> > Non-x86 is the real motivation for the patch, because the flush_write_buffers
> > call in this file is currently not implemented and causes build errors
> > on everything but x86, frv, ia64 and m32r, where the latter two implement
> > it as an empty macro.
> 
> Ok so the FRV would grow a similar no iommu patch to the x86.

Well, not even that. dma-mapping-common.h only makes sense on architectures
that have multiple dma-mapping implementations (parisc, mips, arm, powerpc,
sparc, ia64 and x86, possibly alpha). All others including frv only need a
nommu case anyway and would not use dma-mapping-common.h but could be
changed to use something like the dma-mapping-linear.h I worked on recently.

	Arnd <><

  reply	other threads:[~2009-06-30 13:38 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-06-28 14:39 [PATCH][RFC] asm-generic:remove calling flush_write_buffers() in dma_sync_*_for_cpu tom.leiming
2009-06-28 15:34 ` Arnd Bergmann
2009-06-29 12:31   ` Joerg Roedel
2009-06-29 13:51     ` Ming Lei
2009-06-29 14:45       ` Joerg Roedel
2009-06-29 14:54         ` Ming Lei
2009-06-29 15:44           ` Joerg Roedel
2009-06-29 16:22     ` Arnd Bergmann
2009-06-29 16:31       ` Alan Cox
2009-06-29 16:45         ` Arnd Bergmann
2009-06-29 17:16           ` Alan Cox
2009-06-30 12:34             ` Arnd Bergmann
2009-06-30 12:40               ` Alan Cox
2009-06-30 12:48                 ` Arnd Bergmann
2009-06-30 13:09                   ` Alan Cox
2009-06-30 13:38                     ` Arnd Bergmann [this message]
2009-07-07  1:54                       ` Ming Lei
2009-07-07  7:48                         ` Russell King - ARM Linux
2009-07-07 13:43                           ` Ming Lei
2009-07-07 14:06                             ` Arnd Bergmann
2009-07-07 14:55                               ` Ming Lei
2009-07-07 15:30                                 ` Arnd Bergmann
2009-07-07 17:36                               ` Russell King - ARM Linux
2009-07-07 17:33                             ` Russell King - ARM Linux
2009-06-29 18:47           ` Joerg Roedel
2009-06-29 19:10             ` Alan Cox
2009-06-29 19:24               ` Joerg Roedel
2009-06-29 18:48       ` Joerg Roedel

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