[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20101129193246.GB20761@n2100.arm.linux.org.uk>
Date: Mon, 29 Nov 2010 19:32:46 +0000
From: Russell King - ARM Linux <linux@....linux.org.uk>
To: Paulius Zaleckas <paulius.zaleckas@...il.com>
Cc: Arnd Bergmann <arnd@...db.de>,
linux-arm-kernel@...ts.infradead.org,
Hans Ulli Kroll <ulli.kroll@...glemail.com>,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH] ARM: Gemini: Add support for PCI BUS
On Mon, Nov 29, 2010 at 06:05:07PM +0200, Paulius Zaleckas wrote:
> No he really should NOT use readl/writel. The ONLY difference
> between readl/writel and __raw_readl/__raw_writel is endianess
> conversion. __raw_*l is not doing it. Which to use depend only
> on HW.
Wrong. readl/writel have barriers too to guarantee ordering between
device accesses and memory accesses. (device accesses are already
ordered with respect to themselves.) __raw variants do not
guarantee the relative ordering between memory accesses and device
accesses.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists