[v3,0/2] Add CPU power management for CPU bound CTI devices.

Message

Mike Leach May 11, 2020, 8:48 p.m. UTC

Adds in power management for CPU bound CTI devices:
i) CPU Hotplug - registers a new notifier for CPU start and stop events.
ii) CPU idle PM event notifier to handle PM_ENTER, PM_ENTER_FAILED and
PM_EXIT events.

Tested with DB410c on coresight/next tree (Linux 5.7-rc1)

Changes since v2:
1) removed helper functions filtering on CONFIG_CPU_PM to call cpu_pm
fns directly.
2) add check for return value from cpuhp_remove_state_nocalls().

Changes since V1: (requested by Mathieu).
1) Split into separate patches for CPU pm and CPU hotplug handling.
2) Enable on hotplug has a specific function to enable the hardware,
while leaving the enable reference counts unchanged.

Mike Leach (2):
  coresight: cti: Add CPU Hotplug handling to CTI driver.
  coresight: cti: Add CPU idle pm notifer to CTI devices.

 drivers/hwtracing/coresight/coresight-cti.c | 160 ++++++++++++++++++++
 include/linux/cpuhotplug.h                  |   1 +
 2 files changed, 161 insertions(+)

Comments

Mathieu Poirier May 14, 2020, 5:12 p.m. UTC | #1

On Mon, May 11, 2020 at 09:48:34PM +0100, Mike Leach wrote:
> Adds in power management for CPU bound CTI devices:
> i) CPU Hotplug - registers a new notifier for CPU start and stop events.
> ii) CPU idle PM event notifier to handle PM_ENTER, PM_ENTER_FAILED and
> PM_EXIT events.
> 
> Tested with DB410c on coresight/next tree (Linux 5.7-rc1)
> 
> Changes since v2:
> 1) removed helper functions filtering on CONFIG_CPU_PM to call cpu_pm
> fns directly.
> 2) add check for return value from cpuhp_remove_state_nocalls().
> 
> Changes since V1: (requested by Mathieu).
> 1) Split into separate patches for CPU pm and CPU hotplug handling.
> 2) Enable on hotplug has a specific function to enable the hardware,
> while leaving the enable reference counts unchanged.
> 
> Mike Leach (2):
>   coresight: cti: Add CPU Hotplug handling to CTI driver.
>   coresight: cti: Add CPU idle pm notifer to CTI devices.

I have applied this set.

Thanks,
Mathieu

> 
>  drivers/hwtracing/coresight/coresight-cti.c | 160 ++++++++++++++++++++
>  include/linux/cpuhotplug.h                  |   1 +
>  2 files changed, 161 insertions(+)
> 
> -- 
> 2.17.1
>