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Message-Id: <201010221448.17728.arnd@arndb.de>
Date: Fri, 22 Oct 2010 14:48:17 +0200
From: Arnd Bergmann <arnd@...db.de>
To: cyril@...com
Cc: Andrew Morton <akpm@...ux-foundation.org>,
"davinci-linux-open-source@...ux.davincidsp.com"
<davinci-linux-open-source@...ux.davincidsp.com>,
"spi-devel-general@...ts.sourceforge.net"
<spi-devel-general@...ts.sourceforge.net>,
"broonie@...nsource.wolfsonmicro.com"
<broonie@...nsource.wolfsonmicro.com>,
"lrg@...mlogic.co.uk" <lrg@...mlogic.co.uk>,
"dbrownell@...rs.sourceforge.net" <dbrownell@...rs.sourceforge.net>,
"grant.likely@...retlab.ca" <grant.likely@...retlab.ca>,
"linux-arm-kernel@...ts.infradead.org"
<linux-arm-kernel@...ts.infradead.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"rpurdie@...ys.net" <rpurdie@...ys.net>
Subject: Re: [PATCH v3 01/12] misc: add driver for sequencer serial port
On Friday 22 October 2010 14:39:33 Cyril Chemparathy wrote:
> >> +/* Register Access Helpers */
> >> +static inline u32 ssp_read(struct ti_ssp *ssp, int reg)
> >> +{
> >> + return __raw_readl(ssp->regs + reg);
> >> +}
> >> +
> >> +static inline void ssp_write(struct ti_ssp *ssp, int reg, u32 val)
> >> +{
> >> + __raw_writel(val, ssp->regs + reg);
> >> +}
> >
> > Why are the __raw functions used here?
> >
>
> These registers are to be accessed native endian at all times, and
> therefore the le32 conversion done otherwise is inappropriate.
Won't that break on out-of-order CPUs that need the extra synchronization
done in readl/writel?
Arnd
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