Aw: Re: Re: [PATCH 09/13] PCI: mediatek: Advertise lack of MSI handling

Frank Wunderlich
2021-03-01T14:10:07Z

> Gesendet: Montag, 01. März 2021 um 14:31 Uhr
> Von: "Marc Zyngier" <maz@kernel.org>
>
> Frank,
>
> >> > i guess it's a bug in ath10k driver or my r64 board (it is a v1.1
> >> > which has missing capacitors on tx lines).
> >>
> >> No, this definitely looks like a bug in the MTK PCIe driver,
> >> where the mutex is either not properly initialised, corrupted,
> >> or the wrong pointer is passed.
> >
> > but why does it happen only with the ath10k-card and not the mt7612 in
> > same slot?
>
> Does mt7612 use MSI? What we have here is a bogus mutex in the
> MTK PCIe driver, and the only way not to get there would be
> to avoid using MSIs.

i guess this card/its driver does not use MSI. Did not found anything in "datasheet" [1] or driver [2] about msi

> >
> >> This r64 machine is supposed to have working MSIs, right?
> >
> > imho mt7622 have working MSI
> >
> >> Do you get the same issue without this series?
> >
> > tested 5.11.0 [1] without this series (but with your/thomas' patch
> > from discussion about my old patch) and got same trace. so this series
> > does not break anything here.
>
> Can you retest without any additional patch on top of 5.11?
> These two patches only affect platforms that do *not* have MSIs at all.

i can revert these 2, but still need patches for mt7622 pcie-support [3]...btw. i see that i miss these in 5.11-main...do not see traceback with them (have firmware not installed...)

root@bpi-r64:~# dmesg | grep ath
[ 6.450765] ath10k_pci 0000:01:00.0: assign IRQ: got 146
[ 6.661752] ath10k_pci 0000:01:00.0: enabling device (0000 -> 0002)
[ 6.697811] ath10k_pci 0000:01:00.0: enabling bus mastering
[ 6.721293] ath10k_pci 0000:01:00.0: pci irq msi oper_irq_mode 2 irq_mode 0 r
eset_mode 0
[ 6.921030] ath10k_pci 0000:01:00.0: Failed to find firmware-N.bin (N between
2 and 6) from ath10k/QCA988X/hw2.0: -2
[ 6.931698] ath10k_pci 0000:01:00.0: could not fetch firmware files (-2)
[ 6.940417] ath10k_pci 0000:01:00.0: could not probe fw (-2)

so traceback was caused by missing changes in mtk pcie-driver not yet upstream, added Chuanjia Liu

> >
> >> > Tried with an mt7612e, this seems to work without any errors.
> >> >
> >> > so for mt7622/mt7623
> >> >
> >> > Tested-by: Frank Wunderlich <frank-w@public-files.de>
> >>
> >> We definitely need to understand the above.
> >
> > there is a hardware-bug which may cause this...afair i saw this with
> > the card in r64 with earlier Kernel-versions where other cards work
> > (like the mt7612e).
>
> I don't think a HW bug affecting PCI would cause what we are seeing
> here, unless it results in memory corruption.

[1] https://www.asiarf.com/shop/wifi-wlan/wifi_mini_pcie/ws2433-wifi-11ac-mini-pcie-module-manufacturer/
[2] grep -Rni 'msi' drivers/net/wireless/mediatek/mt76/mt76x2/
[3] https://patchwork.kernel.org/project/linux-mediatek/list/?series=372885