CONFIG_PCIEASPM breaks PCIe on Marvell Armada 385 machine

[Bjorn Helgaas]

On Thu, Jan 12, 2017 at 02:18:46PM +0100, Uwe Kleine-König wrote:
> On 01/11/2017 11:02 PM, Bjorn Helgaas wrote:
> > Hi Uwe,
> > 
> > On Wed, Jan 11, 2017 at 08:49:46PM +0100, Uwe Kleine-König wrote:
> >> Hello,
> >>
> >> on an Marvell Armada 385 based machine (Turris Omnia) with 4.9 the
> >> ath10k driver fails to bind to the matching hardware if CONFIG_PCIEASPM
> >> is enabled:
> >>
> >> [...]
> > We have several open issues related to ASPM:
> > 
> >   https://bugzilla.kernel.org/show_bug.cgi?id=102311 ASPM: ASMEDA asm1062 not working
> >   https://bugzilla.kernel.org/show_bug.cgi?id=187731 Null pointer dereference in ASPM
> >   https://bugzilla.kernel.org/show_bug.cgi?id=189951 Enabling ASPM causes NIC performance issue
> >   https://bugzilla.kernel.org/show_bug.cgi?id=60111 NULL pointer deref in ASPM alloc_pcie_link_state()
> > 
> > I don't recognize yours as being one of these.  Can you open a new
> > issue and attach the complete dmesg log and "lspci -vv" output?
> 
> Done: https://bugzilla.kernel.org/show_bug.cgi?id=192441

Thanks!  Can you attach a dmesg with CONFIG_PCIEASPM turned off, too?

There are several interesting things going on with that ath10k device,
and not all of them seem ASPM-related:

  pci_bus 0000:00: root bus resource [mem 0xe0000000-0xe7ffffff]
  pci 0000:02:00.0: reg 0x10: [mem 0xe8000000-0xe81fffff 64bit]
  pci 0000:02:00.0: reg 0x30: [mem 0xe8200000-0xe820ffff pref]
  pci 0000:02:00.0: of_irq_parse_pci() failed with rc=134
  pci 0000:02:00.0: BAR 0: assigned [mem 0xe0000000-0xe01fffff 64bit]
  pci 0000:02:00.0: BAR 0: error updating (0xe0000004 != 0xffffffff)
  pci 0000:02:00.0: BAR 0: error updating (high 0x000000 != 0xffffffff)

1) We found BAR 0 (reg 0x10) with 0xe8000000, so firmware probably
   programmed it, and it probably works there.

2) The host bridge window doesn't include that BAR 0 space.
   Unfortunately I don't think we print the initial 00:02.0 bridge
   window leading to bus 02; we only print the new window we assign to
   it.

3) No idea what the of_irq_parse_pci() issue is.

4) No idea why the BAR 0 update failed.  Maybe a Marvell config
   accessor problem?

I don't see any connection between these and ASPM, so I'm curious why
things work with CONFIG_PCIEASPM turned off.