On Wed, May 18, 2011 at 9:15 PM, Mohammed Shafi <shafi.wireless@xxxxxxxxx> wrote: > just a quick update, once again I blindly used this patches which > seems to solve the problem, > agg-rx.c still uses the call_rcu thing, so I thought work.c , > aggr-tx.c can make use of call_rcu . > thanks to the guy who mailed this patch! > > need to test more from this thread http://comments.gmane.org/gmane.linux.kernel.wireless.general/69332 will test with compat wireless 16-05-2011 > > > On Wed, May 18, 2011 at 8:16 PM, Mohammed Shafi > <shafi.wireless@xxxxxxxxx> wrote: >> On Wed, May 18, 2011 at 8:11 PM, Larry Finger <Larry.Finger@xxxxxxxxxxxx> wrote: >>> On 05/18/2011 08:04 AM, Mohammed Shafi wrote: >>>> >>>> On Wed, May 18, 2011 at 6:21 PM, Gertjan van Wingerde >>>> <gwingerde@xxxxxxxxx> wrote: >>>>> >>>>> On 05/18/11 14:41, Mohammed Shafi wrote: >>>>>> >>>>>> On Wed, May 18, 2011 at 5:26 PM, Walter Goldens >>>>>> <goldenstranger@xxxxxxxxx> wrote: >>>>>>>>> >>>>>>>>> A very peculiar bug. >>>>>>>>> >>>>>>>>> With compat-wireless from 16.05 a nasty bug started to >>>>>>>> >>>>>>>> manifest itself. Right around association time, the >>>>>>>> rt2800usb causes kernel panic. The system freezes and the >>>>>>>> Caps Lock and Num Lock leds on the keyboard begin to flash. >>>>>>>> >>>>>>>> also ath9k, iwlagn. >>>>>>>> >>>>>>>>> >>>>>>>>> Unfortunately there are no recoverable traces after >>>>>>>> >>>>>>>> the system failure to aid this bug report or to indicate its >>>>>>>> origin. >>>>>>>>> >>>>>>>>> I believe it may somehow be related to Ubuntu's >>>>>>>> >>>>>>>> network-manager. If I turn off the network-manager service, >>>>>>>> I can go into monitor mode for example, but if >>>>>>>> network-manager is running and I plug my USB dongle, it >>>>>>>> starts to associate, a second or two later the system is in >>>>>>>> complete meltdown. >>>>>>>> >>>>>>>> same thing, monitor mode worked perfectly fine. >>>>>>>> >>>>>>>>> >>>>>>>>> Nothing concrete, but a hunch is telling me this has >>>>>>>> >>>>>>>> something to do with the association mechanism of the >>>>>>>> rt2800usb. Compat-wireless from few days back exhibits no >>>>>>>> such foul play. >>>>>>>> >>>>>>>> yes just right at the association complete freeze. >>>>>>>> >>>>>>> >>>>>>> That's strange. I wonder what's the connection with this bug and >>>>>>> network-manager. Because when I manually tried to associate, dmesg reported >>>>>>> the association attempt timed out. >>>>>> >>>>>> no even when we use iw dev connect command we can see the panic. >>>>> >>>>> Yeah, I've seen this freeze as well using one of the later >>>>> compat-wireless packages using just iw and wpa_supplicant to bring up the >>>>> card. This is on all sorts of rt2x00 supported devices. >>>>> >>>>> However, I don't believe this to be an rt2x00-specific bug, as exactly >>>>> the same rt2x00 sources inside a compat-wireless-2.6.39rc7 package do not >>>>> produce the freeze. >>>>> >>>>>> some expert suspected that there is a chance of kfree_rcu in >>>>>> compat-wireless may have caused the problem >>>>>> >>>>> >>>>> That's where my suspicion is as well, but I didn't have the time to >>>>> further investigate. Since my focus was on rt2x00 I used the >>>>> compat-wireless-2.6.39rc7 package to test my patches. I only did a quick >>>>> check, and the kfree_rcu compatibility fix that was done in compat-wireless >>>>> did seem to match the kfree_rcu code is present in linux-next, but maybe >>>>> there is an odd side-effect. >>>> >>>> I could not exactly remember this panic came just after kfree_rcu >>>> backported.. >>> >>> This problem also occurs with rtl8192se from compat-wireless. When it was >>> reported to me, a photo of the console log was included (attached). The >>> crash is a NULL pointer in rcu_do_batch.clone.19 (I think - the photo >>> quality is minimal.). >> >> thanks!, same type of call trace which I had also obtained, hopefully there in >> http://pastebin.com/CZrSZrme >> http://pastebin.com/gwZJGDG4 >> >> >> >>> >>> Larry >>> >>> >>> >>> >> >> >> >> -- >> shafi >> > > > > -- > shafi > -- shafi -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
