From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH] ARM: tegra: Remove 0, prefix from unit-addresses Date: Mon, 11 Apr 2016 12:47:23 -0600 Message-ID: <570BF13B.4060108@wwwdotorg.org> References: <1460383271-27306-2-git-send-email-thierry.reding@gmail.com> <570BCB41.2030504@wwwdotorg.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Rob Herring Cc: Thierry Reding , Alexandre Courbot , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-tegra@vger.kernel.org On 04/11/2016 12:32 PM, Rob Herring wrote: > On Mon, Apr 11, 2016 at 11:05 AM, Stephen Warren wrote: >> On 04/11/2016 08:01 AM, Thierry Reding wrote: >>> >>> From: Thierry Reding >>> >>> When Tegra124 support was first merged the unit-addresses of all devices >>> were listed with a "0," prefix to encode the reg property's second cell. >>> It turns out that this notation is not correct, and the "," separator is >>> only used to separate fields in the unit address (such as the device and >>> function number in PCI devices), not individual cells for addresses with >>> more than one cell. >> >> >>> diff --git a/arch/arm/boot/dts/tegra124-jetson-tk1.dts >>> b/arch/arm/boot/dts/tegra124-jetson-tk1.dts >> >> >>> - gpu@0,57000000 { >>> + gpu@57000000 { >>> /* >>> * Node left disabled on purpose - the bootloader will >>> enable >>> * it after having set the VPR up >> >> >> So the bootloader doesn't actually do that for the new node name at present. >> I have written a patch to make it do so, but haven't sent it yet since I >> wrote it in the middle of a large cleanup of U-Boot. I expect I can shuffle >> it to the front of the series and send it soon though. Without a new >> bootloader that contains this change, IIUC all graphics will be >> non-operative if this change is applied. > > Then you should leave this one alone for a while. > > I also found this looking at u-boot: > > arch/arm/dts/tegra124.dtsi: gpu@57000000 { FWIW, that's because the U-Boot DTs use #address-cells=<1> on this chip so there was no question of using commas in the unit address or not. That may have been because U-Boot imported the DTs (or parts of them) from Linux before Linux switched to #address-cells=<2> on this chip.