On Wednesday, April 30, 2014 1:30:01 pm Don Lewis wrote:
> On 30 Apr, John Baldwin wrote:
> > On Tuesday, April 29, 2014 9:17:19 pm Don Lewis wrote:
> >> On 29 Apr, John Baldwin wrote:
> >> > On Monday, April 28, 2014 8:56:03 pm Don Lewis wrote:
> >>
> >> I just took a closer look at the dmesg output from the two kernels.
> >>
> >> >> agp0: <Intel 82855 host to AGP bridge> on hostb0
> >> >> hostb0: Reserved 0x10000000 bytes for rid 0x10 type 3 at 0xd0000000
> >>
> >> The above line is different with the r262226 kernel:
> >> hostb0: Reserved 0x10000000 bytes for rid 0x10 type 3 at 0
> >
> > Yes, a resource at 0 is going to break things. 9.2 has the NEW_PCIB
option
> > enabled. You can try enabling that for 8.4 to see if it fixes this issue.
> > If it does, it narrows down where to look for the bug.
>
> It behaves the same way with NEW_PCIB. I see hostb at 0 and then the
> hang shortly thereafter.
Ok. hostb isn't actually behind a bridge so that probably makes sense. The
one other reporter who sent me debug output had a BAR on his vgapci0 device
that ended up being at 0 as well (and an active BAR at 0 is pretty much
guaranteed to hose a box).
Are you up for doing some printf sleuthing? There are two odd things that I
see so far:
1) the base address of 0. The question here is if pci_add_map() in
sys/dev/pci/pci.c decides to set start to 0 explicitly, or if it happens
further up the callchain (should be bus_alloc_resource calls in
sys/dev/acpica/acpi_pcib_acpi.c, sys/x86/x86/nexus.c and then in the
rman code itself in sys/kern/subr_rman.c)
2) The 'reserved' printfs during boot probe. Those come from a printf in
pci_alloc_resource() in sys/dev/pci/pci.c. However, that should not be called
until a driver attaches to a device and calls bus_alloc_resource(). It should
not be called from pci_add_child() as it seems to be now.
--
John Baldwin
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