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

[Juergen Gross]

On 01/11/2018 18:30, Michael Kelley wrote:
> 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.

Did you consider using a static_key instead? You could set it in
ms_hyperv_init_platform(). This would enable you to support future
Hyper-V versions which don't require avoiding to set the count to zero.


Juergen