Messages in this thread | | | Subject | Re: 2.6.25-rc8-mm1 panic in rpaphp_register_slot() | From | Benjamin Herrenschmidt <> | Date | Wed, 16 Apr 2008 17:45:16 +1000 |
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On Tue, 2008-04-15 at 21:17 -0600, Alex Chiang wrote: > Hi Ben, > > Could you take a look at this patch and tell me what I'm doing > wrong?
Hrm, I'll have a look but I'd need some context first... This is to fix a problem introduced by another serie of patches ? Can you give me some pointers here ?
The pSeries PCI stuff can be tricky so I'll need some time tomorrow to context switch and remind myself of everything involved :-) So I'd like to make sure by that time, I have all the elements.
Thanks, Ben.
> Thanks. > > /ac > > * Alex Chiang <achiang@hp.com>: > > Hi Badari, > > > > > > > pci_hotplug: PCI Hot Plug PCI Core version: 0.5 > > > > > rpaphp: RPA HOT Plug PCI Controller Driver version: 0.1 > > > > > rpaphp_register_slot registering slot:path[/pci@800000020000003/pci@2,4] index[22010003], name[U787E.001.AAA3015-P2-C1] pdomain[22010003] type[16] > > > > > Unable to handle kernel paging request for data at address 0x00000070 > > > > > > > > Hrm, this is a little more information, but still not quite > > > > enough. I'm going to take a stab in the dark and say I'm probably > > > > doing something wrong on this line, maybe dereferencing a pointer > > > > incorrectly: > > > > > > > > retval = pci_hp_register(php_slot, slot->bus, > > > > PCI_SLOT(PCI_DN(slot->dn->child)->devfn)); > > > > > > Sorry. I thought you knew this already. Disassembly clearly showed > > > that slot->dn->child is NULL. > > > > > > I confirmed it by adding printk also. > > > > This patch is a complete guess on my part (since I've not been > > able to understand pseries architecture) but I think it should > > fix your issue. > > > > Can you give it a try and let me know? It applies on top of the > > -mm tree that includes my physical pci_slot series. > > > > Also, I'm hoping Linas will speak up and let me know what the > > real answer might be. ;) > > > > Thanks. > > > > /ac > > > > From: Alex Chiang <achiang@hp.com> > > Subject: rpaphp: correctly call pci_hp_register for empty PCI slots > > > > Unpopulated device_node slots do not have children, and > > attempting to dereference them will result in a panic. > > > > Instead, attempt to derive the PCI slot number from the bus > > itself, and failing that, default to 0. > > > > Signed-off-by: Alex Chiang <achiang@hp.com> > > --- > > diff --git a/drivers/pci/hotplug/rpaphp_slot.c b/drivers/pci/hotplug/rpaphp_slot.c > > index 0d4cfc7..91ce6a6 100644 > > --- a/drivers/pci/hotplug/rpaphp_slot.c > > +++ b/drivers/pci/hotplug/rpaphp_slot.c > > @@ -121,6 +121,7 @@ int rpaphp_register_slot(struct slot *slot) > > { > > struct hotplug_slot *php_slot = slot->hotplug_slot; > > int retval; > > + int slot_nr; > > > > dbg("%s registering slot:path[%s] index[%x], name[%s] pdomain[%x] type[%d]\n", > > __FUNCTION__, slot->dn->full_name, slot->index, slot->name, > > @@ -132,8 +133,11 @@ int rpaphp_register_slot(struct slot *slot) > > return -EAGAIN; > > } > > > > - retval = pci_hp_register(php_slot, slot->bus, > > - PCI_SLOT(PCI_DN(slot->dn->child)->devfn)); > > + if (slot->bus->self) > > + slot_nr = PCI_SLOT(slot->bus->self->devfn); > > + else > > + slot_nr = 0; > > + retval = pci_hp_register(php_slot, slot->bus, slot_nr); > > if (retval) { > > err("pci_hp_register failed with error %d\n", retval); > > return retval; > > -- > > 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/ > >
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