On Sunday 26 November 2006 14:05, Larry Finger wrote: > Michael Buesch wrote: > > On Sunday 26 November 2006 11:03, Johannes Berg wrote: > >> On Sat, 2006-11-25 at 23:05 -0500, Daniel Drake wrote: > >> > >>> Surely disabling the queue actually makes sense, in order to avoid > >>> frames designated for the "current session" being transmitted on > >>> different channels during scanning? > >> The problem is that queue disabling isn't refcounted so that a scan that > >> collides with bcm43xx having disabled the queue for calibration might > >> re-enable the queue while bcm43xx is still calibrating. > >> > >> Clearly, this doesn't fully fix the problem because softmac will try to > >> transmit frames during the calibration. Hence, a proper fix would be to > >> not remove the calls to netif_tx_disable but make them go through > >> softmac (ieee80211_tx_disable) to make sure that softmac doesn't try to > >> scan while the queues are disabled, which would fix the aforementioned > >> problem of softmac enabling the queue while the driver needs it disabled > >> for free. > > > > Yeah, but I don't think it's worth fixing. ;) > > Simply removing this tx_disable in softmac fixes a _big_ bug > > and that must be applied. The bug of being able to scan while > > calibrating is very minor and not worth to fix. Fixing this > > will likely introduce other bugs. It's simply not worth it > > anymore. > > I actually found one of these while testing WX locking as suggested by Dan > Williams. His method has > two scripts running at the same time with one of them doing an 'iwlist ethX > scan' and the other > executing an 'iwconfig ethX' as fast as possible. Running this test for 36 > hours failed to indicate > any locking errors, but running it without the patch under discussion led to > a number of the > following errors: > > kernel: bcm43xx: ASSERTION FAILED (!ring->suspended) at: > drivers/net/wireless/bcm43xx/bcm43xx_dma.c:71:request_slot() > > This error _NEVER_ happened when softmac was not allowed to disable TX.
Yeah, that's the error I expected. Nice that you proved my point for this being an important patch. ;) -- Greetings Michael. _______________________________________________ Bcm43xx-dev mailing list [email protected] https://lists.berlios.de/mailman/listinfo/bcm43xx-dev
