Re: [Regression, post-2.6.35] ath9k occasionally drops out of PCIconfig space

From: Luis R. Rodriguez
Date: Mon Nov 08 2010 - 16:07:17 EST


On Mon, Nov 8, 2010 at 12:47 PM, Rafael J. Wysocki <rjw@xxxxxxx> wrote:
> On Friday, November 05, 2010, Luis R. Rodriguez wrote:
>> On Fri, Nov 05, 2010 at 01:50:02PM -0700, Rafael J. Wysocki wrote:
>> > Hi,
>> >
>> > For some time I've been experiencing a regression associated with ath9k
>> > that occasionally it drops the connection with the AP and goes into a state
>> > in which reading from its PCI config registers (as done by lspci) return all
>> > ones.
>> >
>> > It may be sort of brought back to life by a suspend/resume afterwards, but
>> > then the driver cannot really handle it and realoding the driver doesn't help
>> > (probe fails). ÂBasically, full machine reboot is needed to revive the adapter.
>> >
>> > The device is:
>> >
>> > 09:00.0 Network controller: Atheros Communications Inc. AR928X Wireless Network Adapter (PCI-Express) (rev 01)
>> > Â Â Â Â Subsystem: Foxconn International, Inc. Device e01f
>> >
>> > and the kernel says:
>> >
>> > [ Â Â9.623217] ath9k 0000:09:00.0: PCI INT A -> GSI 19 (level, low) -> IRQ 19
>> > [ Â Â9.631518] ath9k 0000:09:00.0: setting latency timer to 64
>> > [ Â 10.071497] ath: EEPROM regdomain: 0x65
>> > [ Â 10.071502] ath: EEPROM indicates we should expect a direct regpair map
>> > [ Â 10.071510] ath: Country alpha2 being used: 00
>> > [ Â 10.071514] ath: Regpair used: 0x65
>> > [ Â 10.096025] phy0: Selected rate control algorithm 'ath9k_rate_control'
>> > [ Â 10.097803] Registered led device: ath9k-phy0::radio
>> > [ Â 10.098035] Registered led device: ath9k-phy0::assoc
>> > [ Â 10.098249] Registered led device: ath9k-phy0::tx
>> > [ Â 10.098483] Registered led device: ath9k-phy0::rx
>> > [ Â 10.098496] phy0: Atheros AR9280 Rev:2 mem=0xffffc900017e0000, irq=19
>> >
>> > The issue is not really bisectable, because I'm unable to trigger it on demand
>> > and it occurs approx. 1-2 times a day. ÂSo, if you have any ideas what to test,
>> > please let me know.
>> >
>> > It is not reproducible with the 2.6.35 kernel.
>>
>> Please try this patch.
>
> It _appears_ to help. ÂAt least I haven't been able to reproduce the problem
> since I applied it, which was on Saturday early in the morning.
>
> Still, I also haven't used wireless a lot since that time, because I've been
> traveling mostly.

Thanks, please let us know when you are satisfied with this as a fix.
Its going upstream so either way if you find you hit the issue just
let us know.

Luis
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