PCI trouble on mvebu (Turris Omnia)

Wed Oct 28 12:40:00 EDT 2020

On 28/10/2020 16:08, Toke Høiland-Jørgensen wrote:
> Bjorn Helgaas <helgaas at kernel.org> writes:
>
>> On Wed, Oct 28, 2020 at 02:36:13PM +0100, Toke Høiland-Jørgensen wrote:
>>> 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...
>> I have no personal experience with this device; all I know is that the
>> bugzilla suggests that it worked in v5.4, which isn't much help.
>>
>> Possibly the apparent regression was really a .config change, i.e.,
>> CONFIG_PCIEASPM was disabled in the v5.4 kernel vtolkm@ tested and it
>> "worked" but got enabled later and it started failing?
> Yeah, I suspect so. The OpenWrt config disables CONFIG_PCIEASPM by
> default and only turns it on for specific targets. So I guess that it's
> most likely that this has never worked...
>
>> Maybe the debug patch below would be worth trying to see if it makes
>> any difference?  If it *does* help, try omitting the first hunk to see
>> if we just need to apply the quirk_enable_clear_retrain_link() quirk.
> Tried, doesn't help...
>
> -Toke
>

Found this patch

https://github.com/openwrt/openwrt/blob/7c0496f29bed87326f1bf591ca25ace82373cfc7/target/linux/mvebu/patches-5.4/405-PCI-aardvark-Improve-link-training.patch 

that mentions the Compex WLE900VX card, which reading the lspci verbose 
output from the bugtracker seems to the device being troubled.

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