On Tue, Jul 03, 2012 at 06:50:37PM +0200, Arend van Spriel wrote: > On 07/03/2012 03:45 PM, Seth Forshee wrote: > > Hi Arend, > > > > This message is off-list, only because I know it's been discussed > > on-list in the past. Feel free to pull in any individuals or mailing > > lists if you wish. > > The issue is popping up regularly in Fedora 17. See [1] > > > Brad (on Cc) just received a MacBook Air with BCM4313 wireless, and he's > > able to very reliably trigger the WARN_ON_ONCE in > > brcms_c_wait_for_tx_completion() in his environment. He also gets an > > endless stream of these messages when wireless drops out. > > > > ieee80211 phy0: brcms_c_prec_enq_head: No where to go, prec == 4 > > I only seen this regularly with Fedora 17. Ubuntu 11.04 with 3.5-rc4 > installed in our smoketest setups does not show it. Basically, it means > that packet queue in our driver is full and packets are dropped. As we > do not inform mac80211 that traffic is stalled this is expected to happen. > > > This is in the 3.5-rc kernels. We're carrying the regulatory patches, in > > the Ubuntu kernel, but Brad tested an older rc without the patches and > > still gets this. > > > > We've done a little debugging and have found a couple of points. First, > > all the stack traces I've seen from Brad's machine show that the warning > > triggers during a scan. Second, we added debug to brcms_b_mute() to > > check whether tx was somehow getting muted in the driver without being > > unmuted, but this is not the case. > > I did a little debugging as well and also concluded a scan triggers it. > I change the WARN_ON_ONCE to a WARN_ON and it seems to correlate with > the duration between scan_start and scan_complete. When it is in 8-10 > sec. range the warning kicks in. I was going to add debugging for the tx > mute. > > > I wanted to get in touch with you in case there was anything you wanted > > Brad to try to help with identifying the cause of this issue. Also you > > can find details of his AP setup below. > > The issue is either driver related or caused by firmware behaviour. I > suspect the firmware, but I have not 100% certainty yet. > > Gr. AvS > > [1] https://bugzilla.redhat.com/show_bug.cgi?id=799168 Thanks for the update, Arend. Brad and I are eager to help in any way we can, so please let us know if there's anything we can do to assist. Seth -- 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
