From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ug-out-1314.google.com (ug-out-1314.google.com [66.249.92.174]) by ozlabs.org (Postfix) with ESMTP id 03FB1DDEB7 for ; Fri, 22 Feb 2008 11:01:33 +1100 (EST) Received: by ug-out-1314.google.com with SMTP id q7so1261995uge.0 for ; Thu, 21 Feb 2008 16:01:32 -0800 (PST) Date: Fri, 22 Feb 2008 02:41:36 +0300 From: Anton Vorontsov To: Scott Wood Subject: Re: [PATCH] [POWERPC] 8xx: timebase frequency should not depend on bus-frequency Message-ID: <20080221234136.GA3545@zarina> References: <20080221194508.GA12896@localhost.localdomain> <47BDD587.9060206@freescale.com> <20080221195918.GA14636@localhost.localdomain> <47BDD9E2.5050007@freescale.com> <20080221211343.GA24786@localhost.localdomain> <47BDEB0A.80706@freescale.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 In-Reply-To: <47BDEB0A.80706@freescale.com> Cc: linuxppc-dev@ozlabs.org Reply-To: cbouatmailru@gmail.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Thu, Feb 21, 2008 at 03:20:10PM -0600, Scott Wood wrote: > Anton Vorontsov wrote: > > On Thu, Feb 21, 2008 at 02:06:58PM -0600, Scott Wood wrote: > >> Current u-boots don't support device trees at all on 8xx. > > > > Yes, vanilla u-boots. I assume many of us use some u-boot hacks to > > actually boot with the device tree (no, not cuboots)... ;-) > > Fine, but don't expect misbehavior from out-of-tree u-boots to be used > as justification for the kernel ignoring device tree content. :-) You got me wrong, maybe I wasn't clear enough: it wasn't justification of any kind. It's was just a remark regarding u-boot still not supporting fdt for 8xx (20 lines of code we're lazy to cleanup, write annotation to the patch and send it ;-). Regarding timebase issue. This issue isn't introduced by the u-boots. It is _Linux_ code that is buggy. I'm agree that ideally we should get timebase-frequency from the device tree, but if we'll start getting it from inside the current code, it will look like: ...linux setups tbfreq = cpu_clk / 16... tbfreq = of_get_property(.."timebase-frequency"..); You see? This is illogical, error-prone, and whatnot. :-) I agree, to fix this right way, we should: a) fix current u-boots; b) rework 8xx/ Linux code; and c) rework cuboot for compatibility; Until that happen that tiny patch is a valid bug fix, right? -- Anton Vorontsov email: cbou@mail.ru backup email: ya-cbou@yandex.ru irc://irc.freenode.net/bd2