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From: "Luis R. Rodriguez" <mcgrof@suse.com>
Date: Fri, 26 Jun 2015 18:16:08 -0700
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Subject: Re: [Xen-devel] [PATCH v7 5/9] PCI: Add pci_iomap_wc() variants
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Russell King <linux@arm.linux.org.uk>,
	Stefano Stabellini <stefano.stabellini@eu.citrix.com>
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On Fri, Jun 26, 2015 at 4:54 PM, Benjamin Herrenschmidt
<benh@kernel.crashing.org> wrote:
> On Fri, 2015-06-26 at 15:41 -0700, Luis R. Rodriguez wrote:
>
>> > It wasn't nullified for the main user at the time, the fb. And I
>> > mentioned an IB adapter or two for which the code had been hand
>> tuned.
>>
>> This still means there could be some affected drivers when used on
>> powerpc, no?
>
> Yes. In fact what about things like ARM who also have barriers in their
> writel() ? Won't they also break WC ?

Not sure if they have that write-combine notion on their CPUs /
interconnects. Russel, Stefano, does ARM have write-combining ?

 Luis