usb: dwc3: of-simple: fix use-after-free on remove

Hi,

Adding Rafael and linux-pm to Cc as well.

Quoted 21 lines · Felipe Balbi

This is a direct consequence of not paying attention to the order of things. If driver were to assume that pm_domain->activate() would do the right thing for the device -- meaning that probe would run with an active device --, then we wouldn't need that pm_runtime_get() call on probe at all. Rather we would follow the sequence:

	pm_runtime_forbid()
	pm_runtime_set_active()
	pm_runtime_enable()

	/* do your probe routine */

	pm_runtime_put_noidle()

Then you remove you would need to call pm_runtime_get_noresume() to balance out the pm_runtime_put_noidle() there.

(If you need to know why the pm_runtime_put_noidle(), remember that pm_runtime_set_active() increments the usage counter, so pm_runtime_put_noidle is basically allowing pm_runtime to happen as soon as userspace writes "auto" to /sys/..../power/control)