[PATCH 0/2] i8253: Fix PIT shutdown quirk on Hyper-V

From: Michael Kelley
Date: Thu Nov 01 2018 - 13:30:53 EST


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.

So add a test for running on Hyper-V, and use that test to skip
setting the counter register when running on Hyper-V.

This patch replaces a previously proposed patch with a different
approach. This new approach follows comments from Thomas Gleixner.

Michael Kelley (2):
include/linux/hypervisor.h: Add test for running on Hyper-V
i8253: Fix PIT shutdown quirk on Hyper-V

drivers/clocksource/i8253.c | 14 ++++++++++++--
include/linux/hypervisor.h | 11 +++++++++++
2 files changed, 23 insertions(+), 2 deletions(-)

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1.8.3.1