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

From: Marc Zyngier
Date: Mon Mar 01 2021 - 08:33:09 EST


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.


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.


> Tried with an mt7612e, this seems to work without any errors.
>
> so for mt7622/mt7623
>
> Tested-by: Frank Wunderlich <frank-w@xxxxxxxxxxxxxxx>

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.

Thanks,

M.
--
Jazz is not dead. It just smells funny...