Hi! (I'm sorry, I'm quite out-of-time now). > > Let me reboot my current kernel to test my current five-phase thing, and > > I'll do the subsystem thing too. > > Ok, here. > > This simple patch is nothing but cleanups, cleanups, cleanups. > > And in the process, _I_ think it helps the suspend infrastructure a lot. > > I don't know how many people have ever actually _looked_ closely at how > horrible the ->suspend() sequence was, but let's just say that it was hard > to make sense of how dpm_active->dpm_off worked, and what dpm_off_irq > actually did. More importantly, it was basically impossible for devices to > sanely use the whole dpm_off_irq logic (I doubt anybody ever did - you > would return -EAGAIN to move you into the dpm_off_irq queue, but the > recovery was pretty damn undefined - you'd then get "resumed" even > though you never successfully suspended etc). I was vaguely aware of this hack... and I'm glad you are deleting it. It would be nice to find -EAGAIN users and convert them to new API... just to verify that API is viable. > Btw, if anybody had ever actually used the "dpm_off_irq" thing, they > should have seen a huge warning about the semaphore sleeping with > interrupts off, so I'm pretty sure nobody ever really used it. Since I > think it was unusable, I'm not surprised. I'm pretty sure someone did use it, and just ignored the warning... > The sane version has a very simple sequence: > > - devices start on "dpm_active". > > - "suspend_prepare()" is called for every device (with the semaphore > held, you are _not_ allowed to try to unlink yourself in the prepare > function) Why not just do notifier list here? Very few drivers will actually use this one, and prepare is not really ordered as userspace is running. > And that's it. > > The nice part here is the error management (which, quite frankly, was > insane with the old "dpm_off_irq" scheme). In the new scheme, the > lists Yep, fixing error management is nice, and -EAGAIN was too ugly to live. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
