On Sun, 24 Jan 2021 00:21:13 +0100 Linus Walleij <linus.walleij@xxxxxxxxxx> wrote: > On Sat, Jan 23, 2021 at 4:35 PM Jonathan Cameron <jic23@xxxxxxxxxx> wrote: > > [Me] > > > Next, I think it is better to let suspend/resume, i.e. system PM > > > reuse runtime PM since you're implementing that. This is why > > > we invented PM runtime force resume and force suspend. > > > > Here the driver is turning more off for full suspend than in the > > runtime path. If that results in significant extra delay then > > it's not appropriate to have that in the runtime suspend path. > > I see the point. > > The resume path calls bmi088_accel_enable() which incurs > a 5ms delay. > > The runtime resume path incurs a 1 ms delay. > > The runtime autosuspend kicks in after 2 ms. > > > Maybe the simplification of not doing the deeper power saving > > mode is worth the extra power cost or extra delay, but > > I'm not yet convinced. > > I would personally set the autosuspend to ~20ms and just use > one path and take a hit of 5 ms whenever we go down between > measures if it is a system that is for human interaction, but for > control systems this more complex set-up may be better for > response latencies. > > The current approach may be better tuned to perfection and > we are all perfectionists :D > > I'm just worrying a little about bugs and maintainability. Fully understood. Though for things like this I like to leave it at the discretion of the driver author as fairly safe they are a user of the device. May well make sense to go with the longer times as you suggest though! Over to you Mike :) Jonathan > > Yours, > Linus Walleij
