[Bug 85311] radeon 0000:01:00.0: Max Payload Size 16384, but upstream 0000:00:01.0 set to 128; if necessary, use "pci=pcie_bus_safe" and report a bug

[Bjorn Helgaas]

[+cc linux-pci, linux-pm, Rafael, Alex]

https://bugzilla.kernel.org/show_bug.cgi?id=85311
Every time when I open LID on my notebook I see tons of new error lines in dmesg
with kernel 3.17-rc6. And more lines come from radeon card (dmesg log is attached).
I do not see these log lines with 3.13 kernel, so this is regression.

The new error lines are (from the bugzilla attachment):

i915 0000:00:02.0: BAR 6: [??? 0x00000000 flags 0x2] has bogus alignment
radeon 0000:01:00.0: Max Payload Size 16384, but upstream
0000:00:01.0 set to 128; if necessary, use "pci=pcie_bus_safe" and
report a bug
pci_bus 0000:02: Allocating resources
pci_bus 0000:03: Allocating resources
pci_bus 0000:04: Allocating resources
pci_bus 0000:05: Allocating resources
pci_bus 0000:06: Allocating resources
pci_bus 0000:0e: Allocating resources
i915 0000:00:02.0: BAR 6: [??? 0x00000000 flags 0x2] has bogus alignment
radeon 0000:01:00.0: Max Payload Size 16384, but upstream
0000:00:01.0 set to 128; if necessary, use "pci=pcie_bus_safe" and
report a bug
i915 0000:00:02.0: BAR 6: [??? 0x00000000 flags 0x2] has bogus alignment
radeon 0000:01:00.0: Max Payload Size 16384, but upstream
0000:00:01.0 set to 128; if necessary, use "pci=pcie_bus_safe" and
report a bug
i915 0000:00:02.0: BAR 6: [??? 0x00000000 flags 0x2] has bogus alignment
radeon 0000:01:00.0: Max Payload Size 16384, but upstream
0000:00:01.0 set to 128; if necessary, use "pci=pcie_bus_safe" and
report a bug
i915 0000:00:02.0: BAR 6: [??? 0x00000000 flags 0x2] has bogus alignment
...

Using "radeon.runpm=0" gets rid of the radeon MPS complaints, but not
the others.

When the radeon device is powered down, all the PCI registers and BARs read
back as ones. which is why you are seeing the radeon errors. Apparently the
pci runtime pm code does not properly ask the driver to power the card up
before accessing those registers. Unfortunately, I'm not that familiar with
the Linux runtime pm code. I have no idea about the i915 and apci messages.

I haven't looked into this at all, so I don't know where this bug
report belongs.

Bjorn
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