Fwd: ath10k related kernel crash in wireless-testing (3.12.0-rc3-wl+)

[Kalle Valo]

Kalle Valo <kvalo at qca.qualcomm.com> writes:

> Ben Greear <greearb at candelatech.com> writes:
>
>> I sent this to the wrong list the first time.
>>
>> Do you know if this is already addressed?  If not, I'll see if I can
>> find a fix.
>
> [...]
>
>> ath10k: MSI-X interrupt handling (8 intrs)
>> ath10k: Unable to wakeup target
>> ath10k: target took longer 5000 us to wake up (awake count 1)
>> ath10k: Failed to get pcie state addr: -16
>> ath10k: early firmware event indicated
>> BUG: unable to handle kernel NULL pointer dereference at 0000000000000004
>> IP: [<ffffffffa06ae46c>] ath10k_ce_completed_send_next+0x47/0x122
>> [ath10k_pci]
>
> I think there are two bugs here:
>
> 1) Cold reset doesn't always work, Michal has a patch for that. That's
>    why the wakeup fails:
>
> http://lists.infradead.org/pipermail/ath10k/2013-October/000638.html
>
> 2) We enable interrupts too early and if wakeup fails and we get a
>    spurious interrupt ath10k crashes. We don't have a fix for this yet.

I tried to look how to enable interrupts only after everything is
properly initialised in ath10k, but didn't find any quick way to do
that. I guess one ugly way to workaround this race is to add a state
variable which is checked in the interrupt handler.

Does anyone else have any other ideas?

-- 
Kalle Valo