Re: [RFC] ath9k: Detect and work-around tx-queue hang.

[Ben Greear <greearb@candelatech.com>]

On 02/21/2013 08:49 PM, Sujith Manoharan wrote:
> Ben Greear wrote:
>> I'll be happy to test patches, but I'm not sure how to go about
>> debugging the real problem on my own.  Maybe some stats could
>> be added to the xmit debugfs file to help diagnose the problem,
>> or maybe some other debugfs info will help?
>>
>> I can't reproduce the problem with ath9k debugging set at the
>> previous suggested level, so it would have to be something
>> less invasive.
>>
>> As for just stations going out of range, it remains locked up
>> even with signal level goes back to -20, so it's not just a simple
>> station-out-of range issues..
>
> Sure, but I think that filtered frames are not handled properly,
> especially with aggregation, since the debugfs stats from your earlier email
> showed a large counter (from a private patch ?):
>
> TXERR Filtered:            224          0         0         0

Yeah, guess that patch never made it upstream.  The pertinent bit is:

+++ b/drivers/net/wireless/ath/ath9k/debug.c
@@ -579,6 +579,7 @@ static ssize_t read_file_xmit(struct file *file, char __user *user_buf,
         PR("AMPDUs Completed:", a_completed);
         PR("AMPDUs Retried:  ", a_retries);
         PR("AMPDUs XRetried: ", a_xretries);
+       PR("TXERR Filtered:  ", txerr_filtered);
         PR("FIFO Underrun:   ", fifo_underrun);
         PR("TXOP Exceeded:   ", xtxop);
         PR("TXTIMER Expiry:  ", timer_exp);
@@ -867,6 +868,8 @@ void ath_debug_stat_tx(struct ath_softc *sc, struct ath_buf *bf,
                         TX_STAT_INC(qnum, completed);
         }

+       if (ts->ts_status & ATH9K_TXERR_FILT)
+               TX_STAT_INC(qnum, txerr_filtered);
         if (ts->ts_status & ATH9K_TXERR_FIFO)
                 TX_STAT_INC(qnum, fifo_underrun);
         if (ts->ts_status & ATH9K_TXERR_XTXOP)

I'll post this and a few other small patches when I get a chance.

Thanks,
Ben


-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com