Re: sky2/pci issues on Gigabyte

Linus Torvalds
2007-05-24T22:48:37Z

On Thu, 24 May 2007, Stephen Hemminger wrote:
>
> Looking at the 88e8056 PCI config values:

I think you're looking at the wrong device.

The ones that matter are likely the PCI-X bridge, not the device. The
device cannot reasonably screw up DMA (unless it's really scrogged, but
then it wouldn't work under Vista either).

So it's much more likely to be about device 00:1c.4, which is the bridge
to PCI bus #4:

00:1c.4 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 5
Bus: primary=00, secondary=04, subordinate=04, sec-latency=0

So I'd look at its config space instead ("-" is Vista, "+" is Linux):

-00: 86 80 47 28 07 00 10 00 02 00 04 06 08 00 81 00
+00: 86 80 47 28 07 04 10 00 02 00 04 06 08 00 81 00

10: 00 00 00 00 00 00 00 00 00 04 04 00 b0 b0 00 00

-20: 00 f7 f0 f8 f1 ff 01 00 00 00 00 00 00 00 00 00
+20: 00 f7 f0 f8 01 80 01 80 00 00 00 00 00 00 00 00

-30: 00 00 00 00 40 00 00 00 00 00 00 00 10 01 04 00
+30: 00 00 00 00 40 00 00 00 00 00 00 00 0b 01 04 00

-40: 10 80 41 01 c0 8f 00 00 00 00 10 00 11 24 11 05
+40: 10 80 41 01 c0 8f 00 00 0f 00 11 00 11 24 11 05

50: 40 00 11 30 60 05 a0 00 00 00 48 01 00 00 00 00
60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

-80: 05 90 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+80: 05 90 01 00 0c 10 e0 fe d1 41 00 00 00 00 00 00

90: 0d a0 00 00 58 14 01 50 00 00 00 00 00 00 00 00
a0: 01 00 02 c8 00 00 00 00 00 00 00 00 00 00 00 00
b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Which I _think_ is (I tried to be careful, but..):

Vista Linux

04: 0x00100007 0x00100407
24: 0x0001fff1 0x08018001
3c: 0x00040110 0x0004010b
48: 0x00100000 0x0011000f
80: 0x00009005 0x00019005
84: 0x00000000 0xfee0100c
88: 0x00000000 0x000041d1

but I have not looked at what the _meaning_ of those register
differences are.

The host bridge itself could be the problem, but that one is identical
in the PCI config space. I guess it could also be this one:

00:01.0 PCI bridge: Intel Corporation 82P965/G965 PCI Express Root Port (rev 02) (prog-if 00 [Normal decode])
Bus: primary=00, secondary=01, subordinate=01, sec-latency=0

but I don't know how "port 5" (which is the bus that the ethernet
controller is behind) is related to that "root port" (which is reported
to bridge only subordinate bus 01). The "root port" thing makes me
suspect that device 00:01.0 is somehow related to 00:1c.4 despite the
apparent lack of relationship in the bus topology itself (and the root
port does _not_ decode the IO/MEM resources that lead to the ethernet
chip).

There _are_ differences in that root port device too, but I haven't done
the diff of them yet.

Linus