On Thu, Aug 1, 2019 at 3:35 PM Thomas Gleixner <t...@linutronix.de> wrote: > > On Thu, 1 Aug 2019, Aubrey Li wrote: > > On Thu, Aug 1, 2019 at 2:26 PM Daniel Drake <dr...@endlessm.com> wrote: > > > global_clock_event is NULL here. This is a "reduced hardware" ACPI > > > platform so acpi_generic_reduced_hw_init() has set timer_init to NULL, > > > avoiding the usual codepaths that would set up global_clock_event. > > > > > IIRC, acpi_generic_reduced_hw_init() avoids initializing PIT, the status of > > this legacy device is unknown in ACPI hw-reduced mode. > > > > > I tried the obvious: > > > if (!global_clock_event) > > > return -1; > > > > > No, the platform needs a global clock event, can you turn on some other > > Wrong. The kernel boots perfectly fine without a global clock event. But > for that the TSC and LAPIC frequency must be known.
I think LAPIC fast calibrate is only supported on intel platform, while Daniel's box is an AMD platform. That's why lapic_init_clockevent() failed and fall into the code path which needs a global clock event. Thanks, -Aubrey
