Re: [PATCH V2] Revert "cpufreq: CPPC: Add support for frequency invariance"

[Peter Zijlstra]

On Fri, Jun 11, 2021 at 08:48:02AM +0530, Viresh Kumar wrote:
> This reverts commit 4c38f2df71c8e33c0b64865992d693f5022eeaad.
> 
> There are few races in the frequency invariance support for CPPC driver,
> namely the driver doesn't stop the kthread_work and irq_work on policy
> exit during suspend/resume or CPU hotplug.
> 
> A proper fix won't be possible for the 5.13-rc, as it requires a lot of
> changes. Lets revert the patch instead for now.
> 
> Fixes: 4c38f2df71c8 ("cpufreq: CPPC: Add support for frequency invariance")
> Reported-by: Qian Cai <quic_qiancai@xxxxxxxxxxx>
> Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
> ---
> V2: Revert the original patch instead of marking it broken.
> 
>  drivers/cpufreq/Kconfig.arm    |  10 --
>  drivers/cpufreq/cppc_cpufreq.c | 245 ++-------------------------------
>  include/linux/arch_topology.h  |   1 -
>  kernel/sched/core.c            |   1 -
>  4 files changed, 12 insertions(+), 245 deletions(-)
> 
> diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
> index a5c5f70acfc9..e65e0a43be64 100644
> --- a/drivers/cpufreq/Kconfig.arm
> +++ b/drivers/cpufreq/Kconfig.arm
> @@ -19,16 +19,6 @@ config ACPI_CPPC_CPUFREQ
>  
>  	  If in doubt, say N.
>  
> -config ACPI_CPPC_CPUFREQ_FIE
> -	bool "Frequency Invariance support for CPPC cpufreq driver"
> -	depends on ACPI_CPPC_CPUFREQ && GENERIC_ARCH_TOPOLOGY
> -	default y
> -	help
> -	  This extends frequency invariance support in the CPPC cpufreq driver,
> -	  by using CPPC delivered and reference performance counters.
> -
> -	  If in doubt, say N.
> -

Alternatively: "depends on BROKEN" ?