Well, you're right about stop background scans, it seems to change the way that NM was structured to work.
But lets suppose the use case where you have a embedded system (or a notebook/netbook) and you're running on battery and you don't want use wireless that time and you don't have a rf switch button. You will loose power keeping your wireless card on scanning at each 20 seconds, using passive scan or not. Why don't activate a POWER SAVING mode in nm (when running on battery) and make it decrease the power consumption by turning the wireless card off after X seconds disconnected and only turn it on by client request? On Wed, Jan 14, 2009 at 2:02 PM, Dan Williams <[email protected]> wrote: > On Tue, 2009-01-13 at 23:17 +0200, Antti Kaijanmäki wrote: >> [Aloisio, sorry for double reply, I forgot to CC the list] >> >> On Tue, 2009-01-13 at 17:45 -0300, Aloisio Almeida wrote: >> > Hi all, >> > >> > I noticed that wireless devices are always scanning, and this is very >> > bad to power consuption in embedded systems. >> > I would like to create a way to prevent automatic scan and just >> > perform it when some cliente ask for it. >> > Is it possible to do this? I mean, does it "brake" in some way the nm >> > structure? >> >> Sounds good. Actually if you look at some current embedded devices they >> are performing wireless scan only after user has indicated he wants to >> create a wireless connection. > > I tend to think this is mainly because "it's always been done this way" > rather than for the reason that it's actually a smoother experience for > users. Chips used to suck enough that they actually did require more > power to scan, but these days with passive scans, you don't even need to > TX, and thus you don't need to increase power that much. If this is > really a concern, the best approach is to simply disable the device (or > rfkill or whatever) until the user wants to use it, at which point you > bring the device out of rfkill and let NM go wild. > >> > Actually, I already did this patch to 0.6.6 version, but zero lines >> > applied in new code :) Now i would like to create the patch and submit >> > to upstream. >> > >> > The basic idea is just make can_scan function (src/nm-device-wifi.c) >> > return FALSE due to some user configurations or run flags >> > (--no-bg-scan). In this case, "performScan" dbus method and >> > "ScanPerformed" dbus signal must be created to allow clients to ask >> > for a scan and to notice that the scan has been performed. >> >> Would those be added in org.freedesktop.NetworkManager interface or per >> wireless device in Device.Wireless? > > Not going to happen... Again, we don't just toss stuff in before > actually *understanding* what the problem is, and then determining if > there are better ways of solving the problem instead of these sorts of > hacks. > >> > I'm attaching the 0.6.6 patch, as I said before the idea is the same. >> > >> > Any comments? Is it a good way to implement that? >> >> I would like to have also a dbus option which you can change without >> restarting the daemon; setScanningEnabled() or something like that. >> '--no-bg-scan' would initialize it as false on daemon startup. It could >> be changed during system operation based on power profiles or something >> like that. Anyway it would give more flexibility. Of course that could >> be too close to wirelessEnabled (), though... > > Again, what's the use-case here? Are there better ways of solving this > issue that don't impact the roaming ability performance or user > experience? > > Dan > > > _______________________________________________ NetworkManager-list mailing list [email protected] http://mail.gnome.org/mailman/listinfo/networkmanager-list
