On 07/03/2012 10:09 AM, Seth Forshee wrote: > 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 > Arend, Any progress on this issue? This Macbook Air is barely usable in my environment. It will only stay connected for approx. 30 minutes before I have to reset the wireless. Brad -- Brad Figg brad.figg@xxxxxxxxxxxxx http://www.canonical.com -- 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
