On Thu, Jun 4, 2015 at 11:52 PM, Ingo Molnar <[email protected]> wrote: > > * Andy Lutomirski <[email protected]> wrote: > >> On Thu, Jun 4, 2015 at 4:32 PM, Andy Lutomirski <[email protected]> wrote: >> >> > AFAICT the sole purpose for the hideous x86_64 idle_notifier mess is to >> > support i7300_idle. IMO this junk does not belong in IRQ handling, etc. >> > Can >> > we redo this to work in some kind of generic way? >> > >> > I have no idea why it makes sense to twiddle I/O AT registers in the >> > beginning >> > of whatever IRQ wakes up the CPU. >> > >> > Note that, if absolutely necessary, the ECX bit 0 MWAIT extension can be >> > used >> > to reliably execute code before handling interrupts that wake us from idle. >> > That is, there could be a real cpuidle driver for that chip that does: >> > >> > cli; >> > poke ioat; >> > mwait(ecx = 1); >> > poke ioat; >> > sti; >> > >> > Or we could delete the driver entirely. >> >> It's even easier than that. Just shove the hooks into acpi_idle_do_entry or >> similar and remove them from every other exit_idle call site in the kernel. > > Yes! > > Interested in doing a patch? >
Barely. I don't have the hardware, I have no idea what the registers that i7300_idle pokes are for, and I have no particular desire to start reading the datasheet. I'm not even really sure that i7300 machines use acpi's processor_idle instead of intel_idle. I'm happy to give the driver maintainers a few days to respond. Andy? --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
