On Mon, Jul 21, 2008 at 11:39 AM, Kalle Valo <kalle.valo@xxxxxxxxx> wrote: > "ext Frederic Crozat" <fred@xxxxxxxxxx> writes: > >>> What power-management issues have you seen affecting battery life ? >> >> I think it is usually caused by interoperability deficiency between >> 770/n8x0 and some routers wifi chipset regarding PSM (Power Saving >> Management) part of wifi specification. > > Exactly. The problems stems from the fact PSM was (and still is?) > mostly unused by the windows laptops. So it seems that some AP > manufactures decided to omit the testing of the PSM implementation > altogether. > > Why is PSM so fragile then? Since I can't sleep (jet lag, argh), I'll > write a bit about this. <snip> wow, thanks for the detail explanations. I kind of better understand PSM issues. >> I'm seeing this kind of issue between my work AP (Linksys) which have >> working PSM and my home AP (Freebox, a set-top-box provided by my >> ISP), where PSM is not working properly with a maximum uptime of 8h >> when wifi is on. > > It sounds like PSM is not working at all with your home AP. Yeah, I figured that ;) However, Freebox engineer told me he could see PSM going up and down on the AP side. >> A first bug was found in ralink proprietary driver which was losing >> AP association after some time in PSM mode, which was fixed by >> Ralink. > > Hmm, I would first suspect that the AP is not really buffering all > frames. I have seen APs which periodically send Null frames to check > that the client is really alive. Maybe the AP vendor forgot to check > if the client is sleeping when they send the Null frame? Wouldn't be > the first. I've forwarded your email to Freebox engineer ;) >> If Eero or another Nokia hackers have some information which might >> help Freebox engineers to track the issue, I'll be happy to serve as a >> proxy. > > Dealing with vendors is very slow, it takes hours and hours of work, > consisting mostly writing emails. I simply don't have time for that, > and I rather write code than email. > > But what I could do is to analyse the problem myself. It would take > only an hour or two, including writing a small report about the > problem which I can send everyone interested (hopefully this includes > the vendor). So if you would be able to convince the vendor to send > the AP for a loan? If that's not possible, are you coming to Maemo > Summit? If I manage to come and you can take the AP with you, I could > take a look at it onsite. Unfortunately, it won't be possible because Freebox (the name of set-top-box = ADSL modem + wifi mimo router + many other nice things) can only work when they are synchronized over ADSL with Free ISP DSLAM. So, even if we could send you a Freebox, you couldn't do anything with it :( Anyway, I've pinged Freebox engineer in hope they might have a clue on the issue. > BTW, is there a bug about this? If not, please file one. I'll forward > it to our IOP testers so that they could try get access to the AP as > well. Done : https://bugs.maemo.org/show_bug.cgi?id=3481 -- Frederic Crozat _______________________________________________ maemo-users mailing list maemo-users@xxxxxxxxx https://lists.maemo.org/mailman/listinfo/maemo-users
