Hi,
Kernel is 2.4.0-test12-pre7
I'm seeing an oops while assigning PCI resources on an ARM board. This
board as a PCI to PCI bridge on board without any devices on the second
bus.
Trace is:
Trace; c0013ac0 <pbus_assign_resources+0/e4>
Trace; c0013ba4 <pci_assign_unassigned_resources+0/98>
Trace; c0009f34 <pcibios_init+0/68>
Trace; c0012db4 <pci_init+0/44>
Trace; c00089ec <do_basic_setup+0/54>
The place which is causing the oops is in drivers/pci/setup-bus.c:
for (ln=bus->children.next; ln != &bus->children; ln=ln->next) {
struct pci_bus *b = pci_bus_b(ln);
vvvvvvvvvvvvvvvvvvvvv
b->resource[0]->start = ranges->io_start = ranges->io_end;
^^^^^^^^^^^^^^^^^^^^^
b->resource[1]->start = ranges->mem_start = ranges->mem_end;
pbus_assign_resources(b, ranges);
The reason is because b->resource is NULL. Looking at drivers/pci/pci.c,
when we hit a non-cardbus bridge, we never set b->resource[*] to point to
anything. We call "pci_add_new_bus" from pci_scan_bridge, but neither
pci_add_new_bus nor pci_scan_bridge sets up the resources.
Unfortunately, the PCI bus code (in drivers/pci/setup-bus.c) seems to
assume that someone somewhere has allocated these resources.
_____
|_____| ------------------------------------------------- ---+---+-
| | Russell King [email protected] --- ---
| | | | http://www.arm.linux.org.uk/personal/aboutme.html / / |
| +-+-+ --- -+-
/ | THE developer of ARM Linux |+| /|\
/ | | | --- |
+-+-+ ------------------------------------------------- /\\\ |
Russell King writes:
> I'm seeing an oops while assigning PCI resources on an ARM board. This
> board as a PCI to PCI bridge on board without any devices on the second
> bus.
I've solved this one, sorry for the noise.
_____
|_____| ------------------------------------------------- ---+---+-
| | Russell King [email protected] --- ---
| | | | http://www.arm.linux.org.uk/personal/aboutme.html / / |
| +-+-+ --- -+-
/ | THE developer of ARM Linux |+| /|\
/ | | | --- |
+-+-+ ------------------------------------------------- /\\\ |