pit_shutdown() doesn't work on Hyper-V because of a quirk in the PIT emulation. This problem exists in all versions of Hyper-V and had not been noticed previously. When the counter register is set to zero, the emulated PIT continues to interrupt @18.2 HZ. Account for this quirk by adding a global variable in the i8253 code that controls whether the counter register is zero'ed. Then in Hyper-V initialization code, override the default setting so the counter register is not zero'ed. Changes in v2: * Instead of a function call to check if running on Hyper-V, use a global variable to control whether the counter register is zero'ed. [Juergen Gross & Thomas Gleixner] Michael Kelley (2): i8253: Add support for PIT shutdown quirk x86/hyper-v: Enable PIT shutdown quirk arch/x86/kernel/cpu/mshyperv.c | 11 +++++++++++ drivers/clocksource/i8253.c | 14 ++++++++++++-- include/linux/i8253.h | 1 + 3 files changed, 24 insertions(+), 2 deletions(-) -- 1.8.3.1 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
