Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933404AbaDIOMx (ORCPT ); Wed, 9 Apr 2014 10:12:53 -0400 Received: from mail1.start.ca ([64.140.120.57]:50789 "EHLO mail1.start.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932761AbaDIOMw (ORCPT ); Wed, 9 Apr 2014 10:12:52 -0400 Message-ID: <5345555A.20108@pobox.com> Date: Wed, 09 Apr 2014 10:12:42 -0400 From: Mark Lord User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: Benjamin Herrenschmidt CC: Bjorn Helgaas , "linux-kernel@vger.kernel.org" , Yinghai Lu , "Theodore Ts'o" , "linux-pci@vger.kernel.org" Subject: Re: driver skip pci_set_master, fix it? No. References: <5344251D.7040805@pobox.com> <5344679E.1030008@pobox.com> <1397011868.3671.94.camel@pasglop> <53454660.5090603@pobox.com> In-Reply-To: <53454660.5090603@pobox.com> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 14-04-09 09:08 AM, Mark Lord wrote: > On 14-04-08 10:51 PM, Benjamin Herrenschmidt wrote: >> On Tue, 2014-04-08 at 17:18 -0400, Mark Lord wrote: >>>> I assume you're talking about the one added by cf3e1feba7f9 ("PCI: >>>> Workaround missing pci_set_master in pci drivers"), but as far as I >>>> can tell, it only calls pci_set_master() for *bridge* devices. What >>>> am I missing? Is pci_set_master() being called for your endpoint? >>>> What path is that? >>> >>> Yes, it is being called during execution of the _probe() function in my driver, >>> as evidenced by the annoying (and wrong) message it produces. >>> >>> Next time I've got the hardware at hand, I'll put a "dump_stack()" into there >>> to see the exact calling path. >> >> Note that one of the reason we want to do it early on bridges is that without it, >> we may also not get the PCIe error messages. > > Sure, for bridges. > > I'll get a stack trace later today, but what I suspect is happening > is that this multi-function card is being treated by the PCI layers > as a "bridge" for purposes of the multiple virtual functions it implements. > > We will probably need to distinguish this kind of device from real bridges here. Here's the call trace, all the way back to k7_probe(), the driver's PCI "probe" function, and beyond: [ 30.481454] k7: loading driver version 0.80 [ 30.485561] pcieport 0000:00:1c.0: driver skip pci_set_master, fix it! [ 30.485580] CPU: 2 PID: 4401 Comm: insmod Tainted: G O 3.12.14 #3 [ 30.485583] Hardware name: Supermicro X9SCI/X9SCA/X9SCI/X9SCA, BIOS 2.0b 09/17/2012 [ 30.485590] 0000000000000300 ffff88041c11b9b8 ffffffff8156c40b 0000000000000000 [ 30.485598] ffff88041d2b7000 ffff88041c11b9d8 ffffffff812dc493 0000000000000300 [ 30.485603] ffff88041d399000 ffff88041c11ba08 ffffffff812dc50d 0000000000001000 [ 30.485607] Call Trace: [ 30.485616] [] dump_stack+0x4f/0x84 [ 30.485622] [] pci_enable_bridge+0x93/0xa0 [ 30.485627] [] pci_enable_device_flags+0x6d/0xe0 [ 30.485631] [] pci_enable_device+0xe/0x10 [ 30.485641] [] k7_enable_device+0x3d/0xa30 [k7] [ 30.485649] [] ? k7_devmem_alloc+0x32/0x140 [k7] [ 30.485654] [] ? _raw_spin_lock+0x16/0x40 [ 30.485658] [] ? _raw_spin_unlock+0x11/0x40 [ 30.485666] [] k7_probe+0x458/0x630 [k7] [ 30.485682] [] local_pci_probe+0x46/0x80 [ 30.485696] [] pci_device_probe+0x101/0x110 [ 30.485702] [] driver_probe_device+0x76/0x240 [ 30.485705] [] __driver_attach+0x9b/0xa0 [ 30.485709] [] ? driver_probe_device+0x240/0x240 [ 30.485713] [] bus_for_each_dev+0x55/0x90 [ 30.485717] [] driver_attach+0x19/0x20 [ 30.485720] [] bus_add_driver+0x104/0x290 [ 30.485724] [] driver_register+0x5f/0xf0 [ 30.485728] [] __pci_register_driver+0x46/0x50 [ 30.485736] [] k7_init+0x16e/0x1000 [k7] [ 30.485746] [] ? 0xffffffffa024bfff [ 30.485765] [] do_one_initcall+0x112/0x160 [ 30.485779] [] ? set_memory_nx+0x43/0x50 [ 30.485785] [] load_module+0x1e51/0x2480 [ 30.485789] [] ? show_initstate+0x50/0x50 [ 30.485794] [] SyS_init_module+0x9e/0xc0 [ 30.485799] [] tracesys+0xdd/0xe -- 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/