From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH] OMAP2+: clocksource: fix crash on boot when !CONFIG_OMAP_32K_TIMER Date: Thu, 24 Feb 2011 12:21:57 -0800 Message-ID: <20110224202157.GG20560@atomide.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mho-01-ewr.mailhop.org ([204.13.248.71]:32698 "EHLO mho-01-ewr.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754992Ab1BXUWA (ORCPT ); Thu, 24 Feb 2011 15:22:00 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Paul Walmsley Cc: linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org * Paul Walmsley [110222 18:58]: > > OMAP2+ kernels built without CONFIG_OMAP_32K_TIMER crash on boot after the > 2.6.38 sched_clock changes: > > [ 0.000000] OMAP clockevent source: GPTIMER1 at 13000000 Hz > [ 0.000000] Unable to handle kernel NULL pointer dereference at virtual address 00000000 > [ 0.000000] pgd = c0004000 > [ 0.000000] [00000000] *pgd=00000000 > [ 0.000000] Internal error: Oops: 80000005 [#1] SMP > [ 0.000000] last sysfs file: > [ 0.000000] Modules linked in: > [ 0.000000] CPU: 0 Not tainted (2.6.38-rc5-00057-g04aa67d #152) > [ 0.000000] PC is at 0x0 > [ 0.000000] LR is at sched_clock_poll+0x2c/0x3c > > Without CONFIG_OMAP_32K_TIMER, the kernel has an clockevent and > clocksource resolution about three orders of magnitude higher than > with CONFIG_OMAP_32K_TIMER set. The tradeoff is that the lowest > power consumption states are not available. > > Fix by calling init_sched_clock() from the GPTIMER clocksource init code. I'll queue this as a fix as it's a regression. Tony