PCI trouble on mvebu (Turris Omnia)

[Toke Høiland-Jørgensen]

Toke Høiland-Jørgensen <toke at redhat.com> writes:

> Bjorn Helgaas <helgaas at kernel.org> writes:
>
>> [+cc vtolkm]
>>
>> On Tue, Oct 27, 2020 at 04:43:20PM +0100, Toke Høiland-Jørgensen wrote:
>>> Hi everyone
>>> 
>>> I'm trying to get a mainline kernel to run on my Turris Omnia, and am
>>> having some trouble getting the PCI bus to work correctly. Specifically,
>>> I'm running a 5.10-rc1 kernel (torvalds/master as of this moment), with
>>> the resource request fix[0] applied on top.
>>> 
>>> The kernel boots fine, and the patch in [0] makes the PCI devices show
>>> up. But I'm still getting initialisation errors like these:
>>> 
>>> [    1.632709] pci 0000:01:00.0: BAR 0: error updating (0xe0000004 != 0xffffffff)
>>> [    1.632714] pci 0000:01:00.0: BAR 0: error updating (high 0x000000 != 0xffffffff)
>>> [    1.632745] pci 0000:02:00.0: BAR 0: error updating (0xe0200004 != 0xffffffff)
>>> [    1.632750] pci 0000:02:00.0: BAR 0: error updating (high 0x000000 != 0xffffffff)
>>> 
>>> and the WiFi drivers fail to initialise with what appears to me to be
>>> errors related to the bus rather than to the drivers themselves:
>>> 
>>> [    3.509878] ath: phy0: Mac Chip Rev 0xfffc0.f is not supported by this driver
>>> [    3.517049] ath: phy0: Unable to initialize hardware; initialization status: -95
>>> [    3.524473] ath9k 0000:01:00.0: Failed to initialize device
>>> [    3.530081] ath9k: probe of 0000:01:00.0 failed with error -95
>>> [    3.536012] ath10k_pci 0000:02:00.0: of_irq_parse_pci: failed with rc=134
>>> [    3.543049] pci 0000:00:02.0: enabling device (0140 -> 0142)
>>> [    3.548735] ath10k_pci 0000:02:00.0: can't change power state from D3hot to D0 (config space inaccessible)
>>> [    3.588592] ath10k_pci 0000:02:00.0: failed to wake up device : -110
>>> [    3.595098] ath10k_pci: probe of 0000:02:00.0 failed with error -110
>>> 
>>> lspci looks OK, though:
>>> 
>>> # lspci
>>> 00:01.0 PCI bridge: Marvell Technology Group Ltd. Device 6820 (rev 04)
>>> 00:02.0 PCI bridge: Marvell Technology Group Ltd. Device 6820 (rev 04)
>>> 00:03.0 PCI bridge: Marvell Technology Group Ltd. Device 6820 (rev 04)
>>> 01:00.0 Network controller: Qualcomm Atheros AR9287 Wireless Network Adapter (PCI-Express) (rev 01)
>>> 02:00.0 Network controller: Qualcomm Atheros QCA986x/988x 802.11ac Wireless Network Adapter (rev ff)
>>> 
>>> Does anyone have any clue what could be going on here? Is this a bug, or
>>> did I miss something in my config or other initialisation? I've tried
>>> with both the stock u-boot distributed with the board, and with an
>>> upstream u-boot from latest master; doesn't seem to make any different.
>>
>> Can you try turning off CONFIG_PCIEASPM?  We had a similar recent
>> report at https://bugzilla.kernel.org/show_bug.cgi?id=209833 but I
>> don't think we have a fix yet.
>
> Yes! Turning that off does indeed help! Thanks a bunch :)
>
> You mention that bisecting this would be helpful - I can try that
> tomorrow; any idea when this was last working?

OK, so I tried to bisect this, but, erm, I couldn't find a working
revision to start from? I went all the way back to 4.10 (which is the
first version to include the device tree file for the Omnia), and even
on that, the wireless cards were failing to initialise with ASPM
enabled...

Happy to run other tests, but I think I'm going to need some pointers -
the PCI subsystem is not my home turf :)

-Toke