On Wed, May 29, 2019 at 01:33:46AM +0000, Andy Duan wrote:

> Correct, regmap without device also has issue when power if off, because regmap
> doesn't implement runtime pm for the device, but maybe device driver implement
> the runtime pm for the device. 

> So regmap how to manage the clock and power when access registers by debugfs ?

Like I say the basic recommendation is to use a cache.