Hi Helmut, On Thu, 2009-03-26 at 13:58 -0700, Helmut Schaa wrote: > Am Donnerstag, 26. März 2009 schrieb reinette chatre: > > On Thu, 2009-03-26 at 12:49 -0700, Helmut Schaa wrote: > > > Am Donnerstag, 26. März 2009 schrieb reinette chatre: > > > > On Thu, 2009-03-26 at 12:11 -0700, Helmut Schaa wrote: > > > > > Am Donnerstag, 26. März 2009 schrieb reinette chatre: > > > > > > On Thu, 2009-03-26 at 10:50 -0700, Helmut Schaa wrote: > > > > > > > Hi, > > > > > > > > > > > > > > Am Donnerstag, 26. März 2009 schrieb Reinette Chatre: > > > > > > > > From: Wey-Yi Guy <wey-yi.w.guy@xxxxxxxxx> > > > > > > > > > > > > > > > > Remove STATUS_ALIVE checking when HW RF KILL disabled, the bit get > > > > > > > > clear in __iwl_down() function; the additional checking will fail and > > > > > > > > cause RF can not be turn back on. > > > > > > > > > > > > > > Are you sure this is needed? I'd argue we should only restart the adapter > > > > > > > if it was alive when it got rf_killed. In case the adapter was rf_killed > > > > > > > while the interface was down I don't think we want to restart the adapter > > > > > > > immediately but first when the interface is taken up again. > > > > > > > > > > > > We also need to consider if a suspend/resume happens in the middle. > > > > > > Without the patch, if you enable rfkill, suspend, resume, disable > > > > > > rfkill, then your interface cannot be brought up. > > > > > > > > > > I guess you refer to the situation where the interface is up, right? > > > > > Something like: > > > > > > > > > > - ifconfig wlan0 up > > > > > - press killswitch (kill wireless) > > > > > - suspend > > > > > - resume > > > > > - press killswitch (enable wireless) > > > > > - here the interface should still be up > > > > > > > > > > As the interface is/was up, mac80211's resume handler should restart the > > > > > adapter and thus we wouldn't need to restart the adapter in the > > > > > rfkill-handler, or did I miss anything? > > > > > > > > Yes, the resume handler will start the adapter (call "start"), but the > > > > actions done by it will exit early because of rfkill being enabled. The > > > > STATUS_ALIVE bit will thus not be set after this is completed. Later, > > > > when user disables rfkill, we want to restart the adapter to get all > > > > this corrected, but this call currently fails because of this check. > > > > > > Got it, thanks for the explanation. > > > > > > Nevertheless, removing the check will result in restarting the adapter even > > > if the interface is down. So, I agree that we have a problem here but I do > > > not agree with the solution ;) > > > > I agree that it is not efficient ... but it seems harmless. > > Assume the following situation: > > You only have one killswitch for both, wireless and bluetooth. The wireless > interface is down because it is unused and the user wants to use bluetooth > and enables it via the killswitch which also means that wireless gets > unkilled. Now restarting the adapter needs more power then keeping the > adapter down. In short: if the interface is down the user (space) does not > want to use the interface and probably wants to save power as well. > > > > Maybe taking the interface up (not only pseudo-up, as done currently) should > > > be allowed even if wireless is killed? We already allow the interface to > > > stay up when the adapter gets rfkilled. > > > > Knowing that rfkill is enabled enables us to save power by not bringing > > everything up. > > Yes, but user (space) knows that the wireless card consumes more power if the > interface is up. And if you use NM for example it will just take the interface > down when the killswitch gets activated. > > Another solution would be to > 1) not allow the interface to go up when it is rfkilled, and > 2) take the interface down when it gets rfkilled > > However, I'm not sure if 2 is possible without help of mac80211 and if it > makes sense to change an interface state from within the driver. I was just thinking that some of this thread can be interpreted incorrectly. There is a problem with shared information here ... mac80211 is what brings the interface up and down, yet it is the driver that has the knowledge about rfkill state. There has been talk about having rfkill support in mac80211, but it is not there at this time. Until it is, the driver needs to take care that interface is not fully up (firmware running full throttle) if rfkill enabled, yet let mac80211 think that interface up was successful. Then, when rfkill is disabled we can complete interface bringup. Reinette -- 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
