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From: Arnd Bergmann <arnd@arndb.de>
To: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Joerg Roedel <jroedel@suse.de>, Joerg Roedel <joro@8bytes.org>,
	Kukjin Kim <kgene@kernel.org>,
	Krzysztof Kozlowski <k.kozlowski@samsung.com>,
	linux-arm-kernel@lists.infradead.org,
	iommu@lists.linux-foundation.org,
	linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] iommu: exynos: pointers are nto physical addresses
Date: Mon, 29 Feb 2016 10:54:49 +0100	[thread overview]
Message-ID: <26472865.zD5Ep58Exn@wuerfel> (raw)
In-Reply-To: <56D41087.60506@samsung.com>

On Monday 29 February 2016 10:33:59 Marek Szyprowski wrote:
> > ---
> > I also see that some incorrect __raw_writel() calls have crept in
> > around the same time, which breaks running big-endian kernels when
> > this driver is loaded.
> >
> > Please fix and that that as well.
> 
> Okay, so in the driver code all __raw_writel should be replaced by
> writel(), right?

Yes, writel() is always the safe choice if you don't know what to
use. __raw_writel() should be considered an implementation detail
and not used in drivers at all. There is also writel_relaxed(),
which is faster than writel() because it leaves out all the
barriers (as __raw_writel does too), and you can sometimes use that
in the fast path if you can prove that no barriers are needed.

	Arnd

  reply	other threads:[~2016-02-29  9:55 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-29  8:45 [PATCH] iommu: exynos: pointers are nto physical addresses Arnd Bergmann
2016-02-29  9:33 ` Marek Szyprowski
2016-02-29  9:54   ` Arnd Bergmann [this message]
2016-02-29 15:45 ` Joerg Roedel

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