From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH] Axi-usb: Add support for 64-bit addressing. Date: Mon, 18 Apr 2016 16:35:07 +0200 Message-ID: <4449845.qT8BZnpD4R@wuerfel> References: <1460360506-14692-1-git-send-email-navam@xilinx.com> <4542055.HvdgVkDRYK@wuerfel> <20160418142909.GA5608@rob-hp-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20160418142909.GA5608@rob-hp-laptop> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Rob Herring Cc: mark.rutland@arm.com, devicetree@vger.kernel.org, navam@xilinx.com, pawel.moll@arm.com, hyun.kwon@xilinx.com, ijc+devicetree@hellion.org.uk, Nava kishore Manne , radhey.shyam.pandey@xilinx.com, michal.simek@xilinx.com, balbi@ti.com, linux-kernel@vger.kernel.org, galak@codeaurora.org, soren.brinkmann@xilinx.com, gregkh@linuxfoundation.org, linux-arm-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.org On Monday 18 April 2016 09:29:09 Rob Herring wrote: > > Right, you don't need to know the exact bus width for determining the > register/descriptor set is 32 or 64 bit addesses. I'm fine with a > property for that, but if limiting the actual connected address bits is > needed, then dma-ranges should be used. The other way round: dma-ranges is needed to allow 64-bit addressing, the default is to only allow 32-bit addressing (and arm64 has a known bug here, it just allows it anyway when it shouldn't). Arnd