On Thursday 14 February 2008 02:37:15 pm Linus Torvalds wrote:
On Thu, 14 Feb 2008, Bjorn Helgaas wrote:
That means the PNP system driver has to be registered after the PCI driver.
After the PCI *subsystem*
Here's the actual problem:
[ 31.133141] PCI: Unable to reserve mem region #1:4000@febf8000 for device 0000:00:1b.0
and here is what the resource tree *should* look like:
febf8000-febfbfff : 0000:00:1b.0 febf8000-febfbfff : ICH HD audio
that's with a working sound driver.
Notice how there is *two* resources there: there's the PCI bus resource itself, the one called 0000:00:1b.0 (which was active at boot), and there is the "driver resource" that nests inside of it ("ICH HD audio").
The PCI bus resource is created and inserted into the resource when the PCI bus discovery happens - long before the driver comes along at all.
And the problem is this ABSOLUTE CRAP that happened much earlier:
[ 22.906610] system 00:08: iomem range 0xfebfe000-0xfebfec00 has been reserved [ 22.906654] system 00:08: iomem range 0xfebfa000-0xfebfac00 has been reserved
which happens (a) before the PCI bus probing
I don't think so. pci_scan_bus_parented() happened earlier, here:
[ 22.875359] ACPI: PCI Root Bridge [PCI0] (0000:00)
and pcibios_init() is a subsys_initcall() that happens before the PNP system driver registers via fs_initcall() (I had this order wrong in a previous email).
This has everything to do with the fact that the PnP layer is a piece of crap and overrides/messes with the *correct* resources that we found during PCI bus probing.
There are clearly problems with PNP. I'm trying to help improve the situation.
So here is (for the *fifth* time) what PnP should do:
- only try to insert its resources *after* the PCI bus probing has happened
That already happens.
- and if that fails, LET THE CRAP FAIL instead of making the *good* code fail!
The PNP resource fits entirely inside the PCI bus resource, so the PNP insertion will only fail if the sound driver has already been loaded.
It seems like we're talking past each other. Would anybody else like to step in and help explain this to me? Maybe a fresh viewpoint will help me find a clue.
Bjorn