Thanks for the fix. Acked-by: Yu Zhao <yu.zhao@xxxxxxxxx> On Tuesday, September 02, 2008 2:40 AM, Alex Chiang wrote: >* Zhao, Yu <yu.zhao@xxxxxxxxx>: >> Just happened to see a change in fakephp when searching usage >> of the pci_remove_bus_device(). I couldn't find the original >> patches, but this >> >http://git.kernel.org/?p=linux/kernel/git/jbarnes/pci-2.6.git;a=commitdiff; >h=fe99740cac117f208707488c03f3789cf4904957 >> shows, the pci_remove_bus_device() was removed while the >> remove_slot() was added in disable_slot(), which means: 1) >> fakephp can't remove pci_dev anymore; 2) deadlock happens >> because remove_slot() tries to remove the sysfs entry calling >> itself. > >Sorry about introducing this regression. Does the following patch >fix it for you? > >I've tested it on my system, and I can again use fakephp to >remove a device: > >sapphire:/sys/bus/pci/slots # echo 0 > fake4/power >fakephp: disable_slot - physical_slot = fake4 >e1000 0000:01:02.1: PCI INT B disabled >GSI 32 (level, low) -> CPU 2 (0x0200) vector 54 unregistered >fakephp: Slot already scheduled for removal >fakephp: removing slot fake4 > >We get the "slot already scheduled for removal" because that >particular device has 2 functions, and we're creating slots on a >per-slot basis now, not a per-function basis. > >Although, I wonder, Willy -- is that really the right thing to >do? Seems like fakephp would be more useful if we did operate on >a per-function basis, and not per-slot. Especially given Yu's >work with SR-IOV, where we can apparently have lots of functions >per a physical device. > >Hm? > >Thanks. > >/ac > >From: Alex Chiang <achiang@xxxxxx> > >PCI Hotplug: fakephp: fix deadlock... again > >Commit fe99740cac117f208707488c03f3789cf4904957 (construct one >fakephp slot per PCI slot) introduced a regression, causing a >deadlock when removing a PCI device. > >We also never actually removed the device from the PCI core. > >So we: > > - remove the device from the PCI core > - do not directly call remove_slot() to prevent deadlock > >Yu Zhao reported and diagnosed this defect. > >Signed-off-by: Alex Chiang <achiang@xxxxxx> >--- >diff --git a/drivers/pci/hotplug/fakephp.c b/drivers/pci/hotplug/fakephp.c >index 40337a0..146ca9c 100644 >--- a/drivers/pci/hotplug/fakephp.c >+++ b/drivers/pci/hotplug/fakephp.c >@@ -320,15 +320,15 @@ static int disable_slot(struct hotplug_slot *slot) > return -ENODEV; > } > >+ /* remove the device from the pci core */ >+ pci_remove_bus_device(dev); >+ > /* queue work item to blow away this sysfs entry and other > * parts. > */ > INIT_WORK(&dslot->remove_work, remove_slot_worker); > queue_work(dummyphp_wq, &dslot->remove_work); > >- /* blow away this sysfs entry and other parts. */ >- remove_slot(dslot); >- > pci_dev_put(dev); > } > return 0; -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
