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From: arnd@arndb.de (Arnd Bergmann)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC PATCH] ARM64: PCI: inherit root controller's dma-coherent
Date: Thu, 27 Nov 2014 10:05:57 +0100	[thread overview]
Message-ID: <9101942.u99uxeQ3XX@wuerfel> (raw)
In-Reply-To: <5E6565C8-E868-4559-978A-681045F3582F@redhat.com>

On Thursday 27 November 2014 02:39:59 Jon Masters wrote:
> We're looking at this at the moment (in addition to having the ACPI specification
> clarified to indicate that there is no safe default assumption, requiring that
> DMA masters always indicate their coherency or otherwise via a _CCA whether true
> or false). 

I think for arm64, this should be easy: since ACPI is only for servers, we can
rely on the fact that the devices have cache-coherent DMA all the time. Let's
not over-complicate the ACPI case with all the special hacks we need for embedded.

	Arnd

  reply	other threads:[~2014-11-27  9:05 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-27  5:41 [RFC PATCH] ARM64: PCI: inherit root controller's dma-coherent Ming Lei
2014-11-27  7:39 ` Jon Masters
2014-11-27  9:05   ` Arnd Bergmann [this message]
2014-11-27 11:36     ` Catalin Marinas
2014-11-27 11:53       ` Arnd Bergmann
2014-11-27  9:03 ` Arnd Bergmann
2014-11-27 10:14   ` Ming Lei
2014-11-27 10:22   ` Will Deacon
2014-12-04  3:40   ` Ming Lei
2014-12-05 13:26     ` Grygorii Strashko
2014-12-05 16:05       ` Arnd Bergmann
2014-12-09  2:53         ` Ming Lei
2014-12-10 16:06           ` Arnd Bergmann
2014-12-10 16:23             ` Robin Murphy

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