Hi! > While consolidating the powermac suspend to ram and suspend to disk > implementations to properly use the new framework in kernel/power, among > others, I ended up with the need of adding various callbacks to > kernel/power/main.c. Here is a patch adding & documenting those. > > The reasons I need them are: > > /* Call before process freezing. If returns 0, then no freeze > * should be done, if 1, freeze, negative -> error > */ > int (*pre_freeze)(suspend_state_t state); > > I'm using that one for calling my "old style" notifiers (they are beeing phased > out but I still have a couple of drivers using them). The reason I do that here > is because that's how my APM emulation hooks, and that code interacts with userland > (to properly signal things like X of the suspend process), so I need to do that > before we freeze processes. This should not be needed in future, right? Could it be marked deprecated or something? > /* called after sysdevs and "irq off" devices have been > * worken up, irqs have just been restored to whatever state > * prepare_irqs() left them in. > */ > void (*finish_irqs)(suspend_state_t state); > > This is the pending of the above callback. It gets called after sysdev's > have been woken up but before normal devices have. It's called after the core has > restored local interrupts to what they were upon exit of prepare_irqs(), so if > you do nothing special in prepare_irqs(), you'll get entered with irqs re-enabled > here, while if you exit prepare_irqs() with irqs off, you'll get here with irqs > off as well (and thus become responsible for re-enabling them). > > I want this callback to have finer control of re-enabling interrutps. The interrupt > controller has been partially reconfigured earlier in arch code, but the CPU priority > is only lowered here, so that it starts hitting the CPU again only now. There is > also some code to properly wake up the CPU decrementer so it ticks right away, and > to force taking a pseudo-interrupt (to sort-of "kick" the interrupt controller into > life, seems to work around an issue that I think is related to a HW bug in the > interrupt controller we use). Could you simply reconfigure interrupt controller fully in earlier arch code? > /* called after unfreezing userland */ > void (*post_freeze)(suspend_state_t state); > > That one is the mirror of pre-freeze, gets called after userland has been re-enabled, > it also calls my old-style notifiers, which includes APM emulation, which is important > for sending the APM wakeup events to things like X. Could this be marked deprecated, too? Alternatively, proper way of notifying X (etc) should be created, and done from generic code.... Pavel
