On Fri, Dec 28, 2007 at 03:03:22PM -0800, Andrew Morton wrote: > On Fri, 28 Dec 2007 13:11:37 +0000 "Bahadir Balban" <[EMAIL PROTECTED]> wrote: > > > Hi, > > > > On ARM with PCI, I get this error since -rc2 (didn't try rc1): > > > > sysfs: duplicate filename 'bridge' can not be created > > WARNING: at fs/sysfs/dir.c:424 sysfs_add_one() > > [<c00287fc>] (dump_stack+0x0/0x14) from [<c00cbc64>] > > (sysfs_add_one+0x50/0xf4) > > [<c00cbc14>] (sysfs_add_one+0x0/0xf4) from [<c00ccd30>] > > (sysfs_create_link+0xec/0x184) > > r6:cfca8b48 r5:cfca96c8 r4:cfc2fec0 > > [<c00ccc44>] (sysfs_create_link+0x0/0x184) from [<c0160b44>] > > (pci_bus_add_devices+0xf0/0x144) > > r7:cfc5a2d4 r6:cfc5a2d4 r5:cfc5a2c0 r4:cfcad800 > > [<c0160a54>] (pci_bus_add_devices+0x0/0x144) from [<c0160b30>] > > (pci_bus_add_devices+0xdc/0x144) > > r7:cfc5a3d4 r6:cfc5a3d4 r5:cfc5a3c0 r4:cfcadc00 > > [<c0160a54>] (pci_bus_add_devices+0x0/0x144) from [<c0160b30>] > > (pci_bus_add_devices+0xdc/0x144) > > r7:cfc5a4d4 r6:cfc5a4d4 r5:cfc5a4c0 r4:cfc5d400 > > [<c0160a54>] (pci_bus_add_devices+0x0/0x144) from [<c000a934>] > > (pci_common_init+0x148/0x184) > > r7:c035fd58 r6:cfc3e760 r5:c001e030 r4:cfc5a4c0 > > > > > > Any idea why? > > > > (suitable cc added)
Looks to me as if the code added to pci_bus_add_devices() is off it's rocker. In brief, pci_bus_add_devices() is supposed to be callable given *any* state of the bus, and it will add any new devices found in the bus tree from the bus that it's called for downwards. (That's how I designed that bit of PCI code - so it can cope with hotpluggable PCI bridges.) It still does this. However, some bright spark decided to add sysfs links to it - and break it. Now, whenever we descend into a subordinate bus (and return to a higher level) we will try to create a sysfs symlink even if the bus is one that we already registered. So... that sysfs_create_link() call in there should not be unconditional. It should _only_ ever do that call if list_empty(&dev->subordinate->node) was true. IOW, we only create symlinks for subordinate bus that we don't already know about. It looks like it was introduced by Greg's "PCI: fix __must_check warnings" but why a patch advertised _solely_ as a fix is adding additional sysfs attributes I've no idea. Something like the following should fix it. Bahadir - please test. diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c index 9e5ea07..132a91f 100644 --- a/drivers/pci/bus.c +++ b/drivers/pci/bus.c @@ -131,18 +131,21 @@ void pci_bus_add_devices(struct pci_bus *bus) * it and then scan for unattached PCI devices. */ if (dev->subordinate) { - if (list_empty(&dev->subordinate->node)) { + int new_bus = list_empty(&dev->subordinate->node); + if (new_bus) { down_write(&pci_bus_sem); list_add_tail(&dev->subordinate->node, &dev->bus->children); up_write(&pci_bus_sem); } pci_bus_add_devices(dev->subordinate); - retval = sysfs_create_link(&dev->subordinate->class_dev.kobj, - &dev->dev.kobj, "bridge"); - if (retval) - dev_err(&dev->dev, "Error creating sysfs " - "bridge symlink, continuing...\n"); + if (new_bus) { + retval = sysfs_create_link(&dev->subordinate->class_dev.kobj, + &dev->dev.kobj, "bridge"); + if (retval) + dev_err(&dev->dev, "Error creating sysfs " + "bridge symlink, continuing...\n"); + } } } } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/