Re: [RESEND PATCH 1/2] spi: rockchip: Convert to late and early system PM callbacks

[Dmitry Torokhov]

On Sat, Oct 14, 2017 at 02:25:48AM +0800, jeffy wrote:
> On 10/14/2017 02:19 AM, jeffy wrote:
> > 
> > 
> > it looks like the suspend sequence depends on the dt node sequence, and
> > we are putting display-subsystem dt node above spi dt node, so it would
> > be earlier in the device list, then got suspended later than spi device.
> > 
> > the pwm backlight and cros_ec_spi pwm are very interesting, not only
> > about suspend dependency... if we unbind cros_ec_spi pwm, the pwm
> > backlight would still hold a reference to it, and crash the kernel later.
> 
> or maybe we should move device_pm_add() from device_add() to driver_bound()?

You do not necessarily need to have a driver to power the dveice on and
off.

-- 
Dmitry