Am 03.03.2010 18:06, schrieb Bob Copeland: > On Tue, Mar 2, 2010 at 11:07 AM, Arnd Hannemann > <hannemann@xxxxxxxxxxxxxxxxxxx> wrote: >> Hi, >> >> I'm currently experimenting with ath5k of kernel 2.6.33 in our >> mesh network. We, were previously using madwifi in "ahdemo" mode, >> which worked reasonably well. >> >> At the same time there is no reasonable traffic that justifies this high backlog. >> I'm not yet sure, but it may be related to this message in dmesg: >> >> [ 3681.006797] ath5k phy0: no further txbuf available, dropping packet > > It's likely. > > When this happens, we tell mac80211 to stop all of the > tx queues -- regardless of which queue stopped -- until > the hardware interrupts begin processing tx status > descriptors. We re-enable them when there is a certain > amount of headroom. > >> Any idea how to debug this problem further? > > I would add a printk to where the queues are stopped > and re-enabled, and when packets are queued, to determine > which queue is using up all of the descriptors. I can put > together a patch with the appropriate debug for you if you > like, but in a day or two when I'm a bit less busy. That would be nice. However, I have to wait until saturday to get access to the testbed again... > > By the way, I did notice that if we fail to map DMA > buffers we can leak tx descriptors, but this is unlikely > to be the cause. > Best regards, Arnd -- 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
