From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH] ARM: Do early I/O mapping if spinlock debugging is enabled (Re: [PATCH 3/4] ARM: OMAP3: Add support for 3430 SDP, v3) Date: Thu, 2 Apr 2009 07:54:32 -0700 Message-ID: <20090402145431.GL32530@atomide.com> References: <20090331184802.GA27745@n2100.arm.linux.org.uk> <5A47E75E594F054BAF48C5E4FC4B92AB02FB086086@dbde02.ent.ti.com> <0680EC522D0CC943BC586913CF3768C0036E7EF891@dbde02.ent.ti.com> <20090401220745.GJ32530@atomide.com> <87ocvghsk7.fsf@deeprootsystems.com> <20090402000055.GK32530@atomide.com> <20090402073819.GA4337@n2100.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mho-02-ewr.mailhop.org ([204.13.248.72]:49530 "EHLO mho-02-ewr.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759967AbZDBOyu (ORCPT ); Thu, 2 Apr 2009 10:54:50 -0400 Content-Disposition: inline In-Reply-To: <20090402073819.GA4337@n2100.arm.linux.org.uk> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Russell King - ARM Linux Cc: Kevin Hilman , Paul Walmsley , "Syed Mohammed, Khasim" , "Gadiyar, Anand" , "linux-arm-kernel@lists.arm.linux.org.uk" , "linux-omap@vger.kernel.org" , Juha Yrjola * Russell King - ARM Linux [090402 00:38]: > On Wed, Apr 01, 2009 at 05:00:56PM -0700, Tony Lindgren wrote: > > Well turns out it's the same old bug again Juha tracked down earlier.. > > > > If CONFIG_DEBUG_SPINLOCK is set, and CONFIG_DEBUG_LL is not set, the IO > > does not get mapped. Juha's earlier patch is attached. > > > > Russell, got any better fixes in mind for this? > > No, and as I've said previously, the kernel assuming that sched_clock > is usable before stuff has been initialized is a bug plain and simple. > > Your patch may fix OMAP, but it won't fix everything. > > It's just not going to be possible to make this work. spinlock debugging > needs to stop using sched_clock. Or maybe enable it later on like CONFIG_PRINTK_TIME was changed. Tony