On Tue, 30 Jul 2019 at 14:56, Cornelia Huck <coh...@redhat.com> wrote: > > On Tue, 30 Jul 2019 14:44:21 +0100 > Peter Maydell <peter.mayd...@linaro.org> wrote: > > > On Tue, 30 Jul 2019 at 14:42, Cornelia Huck <coh...@redhat.com> wrote: > > > I'm having a hard time figuring out what a 'cold' or a 'warm' reset is > > > supposed to be... can you add a definition/guideline somewhere? > > > > Generally "cold" reset is "power on" and "warm" is "we were already > > powered-on, but somebody flipped a reset line somewhere". > > Ok, that makes sense... my main concern is to distinguish that in a > generic way, as it is a generic interface. What about adding something > like: > > "A 'cold' reset means that the object to be reset is initially reset; a 'warm' > reset means that the object to be reset has already been initialized." > > Or is that again too generic?
I think it doesn't quite capture the idea -- an object can have already been reset and then get a 'cold' reset: this is like having a powered-on machine and then power-cycling it. The 'warm' reset is the vaguer one, because the specific behaviour is somewhat device-dependent (many devices might not have any difference from 'cold' reset, for those that do the exact detail of what doesn't get reset on warm-reset will vary). But every device should have some kind of "as if you power-cycled it" (or for QEMU, "go back to the same state as if you just started QEMU on the command line"). Our current "reset" method is really cold-reset. thanks -- PMM
