Re: [E1000-devel] e1000e interface hang on 82574L

[Nix <nix@esperi.org.uk>]

On 19 Mar 2012, Carolyn Wyborny said:

>>you'll see that I tested that, and it doesn't work :( even if it did
>>work, it shouldn't be needed: the driver attempts to turn off PCIe ASPM
>>on affected NICs, and fails, apparently because *something* turns it
>>back on again.
>>
> The driver attempts to disable L0s state, not the entire feature. It

It tries to disable L1 state as well (or it did when I tested this last,
although I suspect you're right and it may leave L1 turned on these
days: judging by the contents of e1000_82574_info, anyway.)

> is also required that the device upstream on the bus from the 82574L
> have this disabled. Yes, I agree there appears to be something in the
> os that either ren-enables or fails to disable the feature on the
> upstream device, as desired. Platforms/systems also appear to vary in
> this regard, so the solutions may vary a bit as well.
>
> Its worth trying your solution as well if what I suggested doesn't
> work, but there is not one solution that fits all, unfortunately.

I don't *have* a solution. :( 'setpci by hand some unknown amount of
time after booting once the interface has stabilized' hardly counts as a
solution of any sort. It's, at best, a workaround that lets me use my
systems without hourly lockups until a real solution is found.

(To clarify: manual setpci to force off the ASPM bits is the only thing
that works for me. The driver's automatic disabling of L0s and L1
doesn't work: nor does booting with pcie_aspm=off. In both cases, I end
up with both L0s and L1 turned on, and a lockup some time later, unless
I setpci the bits off by hand.)

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