On 2016-09-07 09:24:57 [+0100], Matt Redfearn wrote: > HI Sebastian, Hi Matt, > > --- a/include/linux/cpuhotplug.h > > +++ b/include/linux/cpuhotplug.h > > @@ -44,6 +44,7 @@ enum cpuhp_state { > > CPUHP_SH_SH3X_PREPARE, > > CPUHP_X86_MICRCODE_PREPARE, > > CPUHP_NOTF_ERR_INJ_PREPARE, > > + CPUHP_MIPS_CAVIUM_PREPARE, > > But I'm curious why we have to create a new state here - this is going to > get very unwieldy if every variant of every architecture has to have it's > own state values in that enumeration. Can this use, what I assume is (and > perhaps could be documented better in include/linux/cpuhotplug.h), the > generic prepare state CPUHP_NOTIFY_PREPARE? We can't share the states - one state is for one callback and one callback only. If you want CPUHP_MIPS_PREPARE and you ensure that this used only _once_ then this can be arranged. For online states we have dynamic allocation of ids (which is what most drivers should use). We don't have this of STARTING + PREPARE callbacks. > Thanks, > Matt > Sebastian