From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH] ARM: tegra: Correct the length of AHB register space Date: Tue, 12 Nov 2013 20:15:30 -0700 Message-ID: <5282EED2.3080603@wwwdotorg.org> References: <1383802327-11908-1-git-send-email-markz@nvidia.com> <52827BF0.5070706@wwwdotorg.org> <5282D200.2090904@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5282D200.2090904-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Mark Zhang , Hiroshi Doyu Cc: "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-tegra@vger.kernel.org On 11/12/2013 06:12 PM, Mark Zhang wrote: > On 11/13/2013 03:05 AM, Stephen Warren wrote: >> On 11/06/2013 10:32 PM, Mark Zhang wrote: >>> On Tegra114 it should be 0x12c. >> >>> diff --git a/arch/arm/boot/dts/tegra114.dtsi b/arch/arm/boot/dts/tegra114.dtsi >> >>> ahb: ahb { >>> compatible = "nvidia,tegra114-ahb", "nvidia,tegra30-ahb"; >>> - reg = <0x6000c004 0x14c>; >>> + reg = <0x6000c004 0x12c>; >>> }; >> >> I don't think this is correct. >> >> 0x12c /is/ the address of the last defined register that exists. >> However, the system memory map table in the TRM indicates that 336 bytes >> of address space are allocated for this module, so the value should be >> 0x150 (minus 4 due to the base address offset of 4, so 0x14c) for all of >> Tegra30/114/124. That matches what's already in DT. >> > > Yeah, but the 0x12c - 0x14c is not defined in TRM, despite the address > space in memory map is 336 bytes. So if you add this section into > register map, that implies writing into this section is OK but this is > undefined behaviour. I'm sure there are plenty of undefined register addresses in all the HW modules in Tegra.