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Subject: Re: RFC on writel and writel_relaxed
To: Will Deacon <will.deacon@arm.com>, Arnd Bergmann <arnd@arndb.de>
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From: Sinan Kaya <okaya@codeaurora.org>
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Date: Tue, 27 Mar 2018 09:46:51 -0400
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On 3/27/2018 7:02 AM, Will Deacon wrote:
> -     See Documentation/DMA-API.txt for more information on consistent memory.
> +     can see it now has ownership.  Note that, when using writel(), a prior
> +     wmb() is not needed to guarantee that the cache coherent memory writes
> +     have completed before writing to the MMIO region.  The cheaper
> +     writel_relaxed() does not provide this guarantee and must not be used
> +     here.

Can we say the same thing for iowrite32() and iowrite32be(). I also see wmb()
in front of these.

-- 
Sinan Kaya
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.