Re: [PATCH] USB :core :Prevent USB devices to autosuspend while setting interface

[Alan Stern]

On Fri, 10 Nov 2017 Abhijeet@xxxxxxxxxxxxxxx wrote:

> From: Abhijeet Kumar <abhijeet.kumar@xxxxxxxxx>
> 
> Runtime resume USB device in order to ensure that PM framework knows
> that the we might be using the device in a short time and doesn't
> autosuspend the device while we update it's interface. Without this
> change, if device autosuspends and the kernel polling for block
> devices is disabled through sysfs at runtime or through bootargs, then
> storage devices might never unmount since the disconnect IRQ wont be
> kicked at all.
> 
> Signed-off-by: Abhijeet Kumar <abhijeet.kumar@xxxxxxxxx>

I don't see any reason for doing this.  The places that call this 
subroutine will already have made sure that the device is active.  
There's no need for an additional runtime_get.

As for disconnect IRQs, they occur whether the device is suspended or 
not (they are generated by the host controller, not by the device).

Alan Stern