[rt2x00-users] [PATCH 0/3] rt2800usb: TX_STA_FIFO read timer

Johannes Stezenbach js at sig21.net
Wed Jan 19 04:50:22 EST 2011


On Tue, Jan 18, 2011 at 06:30:36PM +0100, Ivo Van Doorn wrote:
> > On Tue, Jan 18, 2011 at 04:45:06PM +0100, Johannes Stezenbach wrote:
> >
> > I debugged this a bit because it looked like my patches did not work because
> > of the status timeouts, but it looks like the workqueue is simply blocked
> > by rt2x00queue_flush_queue().
> 
> Yeah I know, that was the rt2x00mac_flush() problem I mentioned before.
> Because rt2x00mac_flush() & Watchdog have a problem with dependencies
> (it depends on the RX/TX work
> structures to run freely), the workqueue on which those structures are
> placed must be in such
> a way that they don't collide with eachother. This causes long delays,
> and long times
> before the client is associated.
> 
> When I comment out the flush() callbacks the association times are
> reduced to normal,
> but I haven't done a stresstest with that function disabled yet.

Ah, OK, I did not understand the workqueue issue completely when you
wrote that email.  I'll try to look into it tomorrow.

FWIW, doing a scan (iwlist wlan0 scan / iw dev wlan0 scan)
also triggers the "failed to flush" warnings, so it's
possible both of the issues from your stresstest might
be connected to that.


Thanks,
Johannes



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