From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt Subject: Re: [PATCH 5/8] powerpc: override dma_get_required_mask by platform hook and ops Date: Thu, 19 May 2011 17:43:56 +1000 Message-ID: <1305791036.7481.52.camel@pasglop> References: <1305152704-4864-1-git-send-email-nacc@us.ibm.com> <1305152704-4864-6-git-send-email-nacc@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1305152704-4864-6-git-send-email-nacc-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org To: Nishanth Aravamudan Cc: cbe-oss-dev-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, FUJITA Tomonori , Sonny Rao , devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Milton Miller , Anton Blanchard , Will Schmidt , Andrew Morton , linuxppc-dev-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org List-Id: devicetree@vger.kernel.org On Wed, 2011-05-11 at 15:25 -0700, Nishanth Aravamudan wrote: > From: Milton Miller > > The hook dma_get_required_mask is supposed to return the mask required > by the platform to operate efficently. The generic version of > dma_get_required_mask in driver/base/platform.c returns a mask based > only on max_pfn. However, this is likely too big for iommu systems > and could be too small for platforms that require a dma offset or have > a secondary window at a high offset. The result of those 3 patches doesn't build on top of my current tree, the generic dma_ops lacks the dma_get_required_mask hook. I'll have a look again after the merge window. Cheers, Ben.