Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932200Ab1DFUnj (ORCPT ); Wed, 6 Apr 2011 16:43:39 -0400 Received: from gra-lx1.iram.es ([150.214.224.41]:40246 "EHLO gra-lx1.iram.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932119Ab1DFUni (ORCPT ); Wed, 6 Apr 2011 16:43:38 -0400 Date: Wed, 6 Apr 2011 22:43:27 +0200 From: Gabriel Paubert To: Dave Airlie Cc: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= , Greg KH , linuxppc-dev@lists.ozlabs.org, LKML Subject: Re: Revert 737a3bb9416ce2a7c7a4170852473a4fcc9c67e8 ? Message-ID: <20110406204327.GA11148@iram.es> References: <20110404235259.GA30132@iram.es> <20110406084101.GB13963@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4385 Lines: 85 On Wed, Apr 06, 2011 at 06:46:55PM +1000, Dave Airlie wrote: > 2011/4/6 Uwe Kleine-K?nig : > > Hi Gabriel, > > > > On Tue, Apr 05, 2011 at 01:52:59AM +0200, Gabriel Paubert wrote: > >> I've had the following funny crashes on PPC machines, with > >> cataleptic X server as a consequence: > >> > >> kernel: [drm] Setting GART location based on new memory map > >> kernel: Oops: Exception in kernel mode, sig: 4 [#1] > >> kernel: CHRP > >> kernel: last sysfs file: /sys/devices/pci0001:01/0001:01:08.0/resource > >> kernel: NIP: c05648fc LR: c0226f58 CTR: 00000008 > >> kernel: REGS: ddb53d20 TRAP: 0700 ? Not tainted ?(2.6.38) > >> kernel: MSR: 00089032 ?CR: 48044482 ?XER: 00000000 > >> kernel: TASK = ddab12b0[3040] 'Xorg' THREAD: ddb52000 > >> kernel: GPR00: c0226f34 ddb53dd0 ddab12b0 00000000 c0509e6c 00000000 00000000 00000000 > >> kernel: GPR08: 00000000 00000000 00000000 00000000 28044488 101f3d8c bf8166b4 00002c00 > >> kernel: GPR16: 101b9458 1006f1a0 101ebe0c 00000001 101ebe08 00000000 df9efc20 df9efc00 > >> kernel: GPR24: c0591e54 80546440 ddacf660 df9efc00 c0506048 c0480210 00a00000 df9ef800 > >> kernel: NIP [c05648fc] platform_device_register_resndata+0x4/0xa4 > >> kernel: LR [c0226f58] radeon_cp_init+0xd08/0x10c4 > >> kernel: Call Trace: > >> kernel: [ddb53dd0] [c0226f34] radeon_cp_init+0xce4/0x10c4 (unreliable) > >> kernel: [ddb53df0] [c020801c] drm_ioctl+0x2c0/0x3e4 > >> kernel: [ddb53eb0] [c0091264] do_vfs_ioctl+0x674/0x710 > >> kernel: [ddb53f10] [c0091340] sys_ioctl+0x40/0x70 > >> kernel: [ddb53f40] [c00111a8] ret_from_syscall+0x0/0x38 > >> kernel: --- Exception: c01 at 0xfc54a78 > >> kernel: ? ? LR = 0xfc549dc > >> kernel: Instruction dump: > >> kernel: 736f2e31 32002f75 73722f6c 69622f6c 6962786b 6c617669 65722e73 6f2e3132 > >> kernel: 006c6962 786b6266 696c652e 736f2e31 <002f7573> 722f6c69 622f6c69 62786b62 > >> kernel: ---[ end trace ed79daba161e31d9 ]--- > >> > >> As you can see, the processor is trying to execute ASCII strings like > >> "/usr/lib/libxkb" and has trouble digesting them :-) > >> > >> The backtrace is actually missing radeon_cp_init_microcode and radeon_do_init_cp > >> which are inlined inside radeon_cp_init. > >> > >> The trouble is that radeon_cp_init_microcode calls platform_device_register_simple > >> which is a simple inline wrapper around platform_device_register_resndata, which > >> happens to be already freed and overwritten with something looking like a list > >> of filenames, since I have a non modular kernel. > >> > >> For now I have locally reverted 737a3bb9416ce2a7c7a4170852473a4fcc9c67e8 > >> which simply added an _init_or_module section attribute to > >> platform_device_register_resndata, and X is up again... > >> > >> Now it may be that it is the ioctl that does not have the right to do > >> this. Actually I thought that the name radeon_cp that is registered there > >> would appear somwhere under /sys (or /proc) but failed to find it... > > I don't know for sure, but it looks strange to me that an ioctl can > > register a device. But the fear for such code in the kernel made me > > choose not to squash 737a3bb941 into 44f28bdea094. So my POV is that if > > the maintainer of the radeon driver thinks registering the device is OK, > > reverting 737a3bb9416 is fine for me. > > This is the old DRM driver for radeon, which relies on userspace to > start X then calls the kernel > to initialise the hardware. Due to this model, there is no device we > can hang off (the PCI device > might already be bound to fbdev), so we are forced to create a > platform device to load the firmware. > > So its ugly, unless someone can suggest a better device to hang things > off I don't know of another way. > The probem is that, at least on one of my machines, the new driver does not work: the system hangs (apparently solid, but it's before networking starts up and I've not yet hooked up a serial console), after the "radeon: ib pool ready" message. With the old driver, I've found some combinations of configuration options that works. They all fail when DRM_RADEON_KMS is enabled. Gabriel > Dave. -- 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/