[PATCH RFC v4 1/3] PM / Runtime: Add an API pm_runtime_set_slave

Alan Stern stern at rowland.harvard.edu
Mon Feb 9 07:58:41 PST 2015


On Mon, 9 Feb 2015, Amit Daniel Kachhap wrote:

> This API creates a pm runtime slave type device which does not itself
> participates in pm runtime but depends on the master devices to power
> manage them.

This makes no sense.  How can a master device manage a slave device?  
Devices are managed by drivers, not by other devices.

>  These devices should have pm runtime callbacks.
> 
> These devices (like clock) may not implement complete pm_runtime calls
> such as pm_runtime_get/pm_runtime_put due to subsystems interaction
> behaviour or any other reason.
> 
> Signed-off-by: Amit Daniel Kachhap <amit.daniel at samsung.com>
> ---
>  drivers/base/power/runtime.c | 18 ++++++++++++++++++
>  include/linux/pm.h           |  1 +
>  include/linux/pm_runtime.h   |  2 ++
>  3 files changed, 21 insertions(+)

This patch is unacceptable because it does not update the runtime PM 
documentation file.

Besides, doesn't the no_callbacks flag already do more or less what you 
want?

Alan Stern




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