From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id A7EBEB70F1 for ; Wed, 22 Sep 2010 15:41:59 +1000 (EST) Subject: Re: [PATCH] fsldma: add support to 36-bit physical address Mime-Version: 1.0 (Apple Message framework v1081) Content-Type: text/plain; charset=us-ascii From: Kumar Gala In-Reply-To: Date: Wed, 22 Sep 2010 00:41:43 -0500 Message-Id: <492E9153-2D3E-4DA2-AD04-4F92C94DB3A7@kernel.crashing.org> References: <1285066638-7473-1-git-send-email-leoli@freescale.com> <877FD0B5-19A7-4A16-831E-369B80B104EA@kernel.crashing.org> <20100921163456.7e2c9b32@udp111988uds.am.freescale.net> <20100921164944.164ed0af@udp111988uds.am.freescale.net> <2C3F2C02-35B6-46AF-82DA-44ACCBFB8362@digitaldans.com> <20100921171746.381f2e89@udp111988uds.am.freescale.net> To: Timur Tabi Cc: "linux-kernel@vger.kernel.org List" , Scott Wood , Dan Malek , linuxppc-dev , Dan Williams List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Sep 21, 2010, at 5:34 PM, Timur Tabi wrote: > On Tue, Sep 21, 2010 at 5:17 PM, Scott Wood = wrote: >=20 >> It needs to be the actual device that is performing the DMA -- the >> platform may need to do things such as IOMMU manipulation where >> knowing the device matters. >=20 > Ok, this all makes sense. So it appears that the patch is valid, at > least in theory. I would like to see some testing of it, but I > realize that may be too difficult. There's no easy way to force an > allocation above 4GB. I think the patch is pretty safe w/o testing. However I agree we need a = better solution to testing 36-bit addressing. - k=