Hi! On Sun, 25 Feb 2018 13:20:14 +0000 Nicholas Mc Guire wrote: > the decrement though is conditional: > pm_runtime_put_noidle > -> atomic_add_unless(&dev->power.usage_count, -1, 0); pm_runtime_put_noidle is playing it safe by not decrementing past 0, I think that's a good thing. > Also just wondering - could one not decrement in pm_runtime_get_sync > on the error path rather than defering this to the caller and fixing > it there ? That's what I've asked linux-pm in the linked discussion: > > https://marc.info/?l=linux-pm&m=151904483924999&w=2 As far as I've understood the idea is that most "error" return values actually are a result of disabled runtime PM, and that should be transparent to the caller. Looking at the code, that's what the vast majority of callers do - they just ignore the return value of pm_runtime_get_sync, and somewhere later have an unconditional pm_runtime_put_... call. So the only issue are callers that don't ignore the pm_runtime_get_sync return value, probably because they're having some kind of special requirements for error handling. For those, they need to ensure that a proper _put_ is done somewhere in the error path. > Reviewed-by: Nicholas Mc Guire <der.herr@xxxxxxx> Thanks for the review!, Tobias
