On Sat, Dec 11, 2004 at 01:43:05PM +0000, wlacey wrote:
> Might someone be willing to share a bit knowledge with me?
>
> I've transitioned to the 2.6.10 kernel and I'm having a difficult time understanding what things I must do different to get my pci slots probed as before in 2.4. At this point I'm well aware the 2.6 is not a drop in replacement for 2.4 but what is the a general approach to getting something like PCI_AUTO capability in 2.6 what steps must I take and is there document describing them.
PCI_AUTO was really, really broken code. It only works for some subset
of systems, won't handle hot plugging (Cardbus!), PCI-PCI bridges and many
other cases. The world became a better place on the day when it got
removed.
> I call register_pci_controller() but the bus is never scanned becasue pcibios_init() fails out with...
> "Skipping PCI bus scan due to resource conflict"
The new PCI code by default will fully configure a PCI bus hierarchy. For
this to work it needs to know which memory address range and which I/O
port address range are available for assignment. This information is
passed in the struct pci_controller argument of register_pci_controller().
Here's a simplified example from arch/mips/sni/setup.c:
static struct resource sni_io_resource = {
"PCIMT IO MEM", 0x00001000UL, 0x03bfffffUL, IORESOURCE_IO,
};
static struct resource sni_mem_resource = {
"PCIMT PCI MEM", 0x10000000UL, 0xffffffffUL, IORESOURCE_MEM
};
extern struct pci_ops sni_pci_ops;
static struct pci_controller sni_controller = {
.pci_ops = &sni_pci_ops,
.mem_resource = &sni_mem_resource,
.mem_offset = 0x10000000UL,
.io_resource = &sni_io_resource,
.io_offset = 0x00000000UL
};
That is PCI memory is in the address range of 0x10000000UL - 0xffffffffUL
and I/O ports in the range 0x00001000UL - 0x03bfffffUL. The io_offset
rsp. mem_offset values say how much needs to be added rsp. subtracted
when converting a PCI bus address into a physical address. Often these
values are either the same a the resource's start address or zero.
I hope that explains things a little ...
Ralf
