Date: Tue, 30 Jun 2009 14:09:45 +0100
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Arnd Bergmann <arnd@arndb.de>
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
Message-ID: <20090630140945.0784e174@lxorguk.ukuu.org.uk>
In-Reply-To: <200906301448.55064.arnd@arndb.de>
References: <1246199959-6548-1-git-send-email-tom.leiming@gmail.com>
	<200906301434.26815.arnd@arndb.de>
	<20090630134000.23674147@lxorguk.ukuu.org.uk>
	<200906301448.55064.arnd@arndb.de>
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 941
Lines: 20

> > 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.

> The only users of the file right now are x86 and ia64, and ia64 only added
> the empty flush_write_buffers() definition in order to use it.

That now all makes sense.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/