Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750975AbWIUTi0 (ORCPT ); Thu, 21 Sep 2006 15:38:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751359AbWIUTiZ (ORCPT ); Thu, 21 Sep 2006 15:38:25 -0400 Received: from smtp.osdl.org ([65.172.181.4]:24733 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1750975AbWIUTiZ (ORCPT ); Thu, 21 Sep 2006 15:38:25 -0400 Date: Thu, 21 Sep 2006 12:37:42 -0700 From: Andrew Morton To: Olaf Hering Cc: linux-kernel@vger.kernel.org, linux-fbdev-devel@lists.sourceforge.net, "Antonino A. Daplas" , Daniel R Thompson , Michael Hanselmann , Jon Smirl Subject: Re: backlight: oops in __mutex_lock_slowpath during head /sys/class/graphics/fb0/* in 2.6.18 Message-Id: <20060921123742.ec225cc2.akpm@osdl.org> In-Reply-To: <20060921121952.GA16927@aepfle.de> References: <20060921121952.GA16927@aepfle.de> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.6; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3382 Lines: 80 On Thu, 21 Sep 2006 14:19:52 +0200 Olaf Hering wrote: > The bl_curve code has some room for improvement. > > ... > <6>Monitor sense value = 0x60b > <6>using video mode 13 and color mode 0. > <4>Console: switching to colour frame buffer device 104x39 > <6>fb0: valkyrie frame buffer device > ... > > inst-sys:~ # cat /proc/fb > 0 valkyrie > inst-sys:~ # l /sys/class/graphics/fb0/ > total 0 > drwxr-xr-x 2 root root 0 Sep 21 11:54 ./ > drwxr-xr-x 4 root root 0 Sep 21 11:53 ../ > -rw-r--r-- 1 root root 4096 Sep 21 12:15 bits_per_pixel > -rw-r--r-- 1 root root 4096 Sep 21 12:15 bl_curve > -rw-r--r-- 1 root root 4096 Sep 21 12:15 blank > -rw-r--r-- 1 root root 4096 Sep 21 12:15 console > -rw-r--r-- 1 root root 4096 Sep 21 12:15 cursor > -r--r--r-- 1 root root 4096 Sep 21 12:15 dev > -rw-r--r-- 1 root root 4096 Sep 21 12:15 mode > -rw-r--r-- 1 root root 4096 Sep 21 12:15 modes > -r--r--r-- 1 root root 4096 Sep 21 12:15 name > -rw-r--r-- 1 root root 4096 Sep 21 12:15 pan > -rw-r--r-- 1 root root 4096 Sep 21 12:15 rotate > -rw-r--r-- 1 root root 4096 Sep 21 12:15 state > -r--r--r-- 1 root root 4096 Sep 21 12:15 stride > lrwxrwxrwx 1 root root 0 Sep 21 12:15 subsystem -> ../../../class/graphics/ > --w------- 1 root root 4096 Sep 21 12:15 uevent > -rw-r--r-- 1 root root 4096 Sep 21 12:15 virtual_size > inst-sys:~ # head /sys/class/graphics/fb0/* > ==> /sys/class/graphics/fb0/bits_per_pixel <== > 8 > > ==> /sys/class/graphics/fb0/bl_curve <== > Segmentation fault > inst-sys:~ # dmesg > valkyriefb: vmode 13 does not support cmode 1. > Unable to handle kernel paging request for data at address 0x00000000 > Faulting instruction address: 0xc02c7bd8 > Oops: Kernel access of bad area, sig: 11 [#1] > > Modules linked in: tulip mesh cpufreq_ondemand loop nfs nfs_acl lockd sunrpc sg st sd_mod sr_mod scsi_mod ide_cd cdrom > NIP: C02C7BD8 LR: C0170EBC CTR: C0170E90 > REGS: c4209db0 TRAP: 0300 Not tainted (2.6.18-rc7-git1-2-default) > MSR: 00009032 CR: 28042488 XER: 00000000 > DAR: 00000000, DSISR: 22000000 > TASK = c7fc8190[2853] 'head' THREAD: c4208000 > GPR00: C4209E6C C4209E60 C7FC8190 C0B77614 C41D5000 C41D5000 00000000 00008000 > GPR08: 00000000 C0B77618 00000000 00000000 00000000 100200C8 10020000 00000001 > GPR16: 10006D08 7FDF9B3C 100A0000 10080000 00000003 7FDF9CAB C4209F20 C2FCDC78 > GPR24: C038BC14 C01EF568 7FDF7858 C41D5000 C0B77614 C0B77400 C7FC8190 C0B77614 > NIP [C02C7BD8] __mutex_lock_slowpath+0x2c/0xa4 > LR [C0170EBC] show_bl_curve+0x2c/0xa0 > Call Trace: > [C4209E60] [C02C7A54] mutex_lock+0x18/0x5c (unreliable) > [C4209E80] [C0170EBC] show_bl_curve+0x2c/0xa0 > [C4209EB0] [C01EF594] class_device_attr_show+0x2c/0x44 > [C4209EC0] [C00CC3BC] sysfs_read_file+0xb8/0x204 > [C4209EF0] [C0083FE4] vfs_read+0xec/0x1c8 > [C4209F10] [C0084444] sys_read+0x4c/0x8c > [C4209F40] [C00125F8] ret_from_syscall+0x0/0x40 > --- Exception: c01 at 0xff589f8 > LR = 0x100045e0 > Instruction dump: > 4e800020 9421ffe0 7c0802a6 39230004 bfc10018 7c7f1b78 7c5e1378 90010024 > 3801000c 9121000c 81690004 90090004 <900b0000> 91610010 90410014 3800ffff > cc's added. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/