Re: Kernel oops in ath9k

[Pavel Roskin <proski@gnu.org>]

On Thu, 2009-11-19 at 09:54 -0500, Douglass, Woodrow wrote:
> Hi all,
> 
> I'm not sure if this is the right place to post this, but I may have a
> bug report for the ath9k driver.

You may want to post to ath9k-devel@lists.ath9k.org, as the problem
seems to be specific to the Atheros driver.

> I'm running a single board computer with a 600Mhz celeron processor. On
> the minipci bus I have a Ubiquiti SR71-12 802.11n card.

It would be helpful if you also specified the exact version of the
kernel.

>  Also attached is
> a shell script with the commands I run to cause the oops. Note that the
> first time the ifconfig line in this script is run, a "SIOCSIFFLAGS:
> Input/Output Error" is triggered, the kernel oops happens about 5
> seconds after the ifconfig line is run a second time.

I can reproduce "Input/Output Error" with SR71-12, but not the oops with
the current linux-wireless.

I know that it's caused by returning false in this code in file
drivers/net/wireless/ath/ath9k/calib.c, function ath9k_hw_init_cal():

                /* Poll for offset calibration complete */
                if (!ath9k_hw_wait(ah, AR_PHY_AGC_CONTROL, AR_PHY_AGC_CONTROL_CAL,
                                   0, AH_WAIT_TIMEOUT)) {
                        ath_print(common, ATH_DBG_CALIBRATE,
                                  "offset calibration failed to "
                                  "complete in 1ms; noisy environment?\n");
                        return false;
                }

With full debugging (modprobe ath9k debug=0xffffffff), the kernel
messages are (with some context):

ath: Reset TXQ, inactive queue: 7
ath: Reset TX queue: 8
ath: tx ok 0x0 err 0x0 desc 0x10f eol 0x10f urn 0x0
ath: Reset TX queue: 9
ath: tx ok 0x0 err 0x0 desc 0x10f eol 0x10f urn 0x0
ath: ah->misc_mode 0x4
ath: timeout (100000 us) on reg 0x9860: 0xdeadbeef & 0x00000001 != 0x00000000
ath: offset calibration failed to complete in 1ms; noisy environment?
ath: Unable to reset hardware; reset status -5 (freq 2412 MHz)

I have access to various Ubiquiti cards, but SR71-12 is the only one
that fails.  I know that it works in Windows XP with the Ubiquiti driver
for other SR71 cards (the inf file should be tweaked to recognize the
revision of SR71-12).  That makes me think the problem is not in the
hardware and not in the noisy environment.

ath9k identifies the card as:

phy0: Atheros AR9280 Rev:2 mem=0xffffc90010da0000, irq=18

# lspci -vnn -s 03:01.0
03:01.0 Network controller [0280]: Atheros Communications Inc. AR922X
Wireless Network Adapter [168c:0029] (rev 01)
        Subsystem: Device [0777:4002]
        Flags: bus master, 66MHz, medium devsel, latency 168, IRQ 18
        Memory at fe3f0000 (32-bit, non-prefetchable) [size=64K]
        Capabilities: [44] Power Management version 2
        Kernel driver in use: ath9k
        Kernel modules: ath9k

-- 
Regards,
Pavel Roskin