[PATCH v3 1/1] USB: core: let USB device know device node

Peter Chen hzpeterchen at gmail.com
Mon Jan 18 18:52:54 PST 2016


On Mon, Jan 18, 2016 at 11:39:06AM -0500, Alan Stern wrote:
> On Mon, 18 Jan 2016, Peter Chen wrote:
> 
> > > > Why can't the root_hub reuse dev->dev.of_node?
> > > 
> > > Indeed, there's no need to add an .of_node field to struct usb_device, 
> > > since the embedded struct device already contains an .of_node field.
> > > 
> > 
> > No, the usb_device needs the .of_node field.
> 
> It already _has_ an .of_node field, in its embedded struct device.
> 
> > The devices belong to platform bus contains device node.
> > The devices (usb device) belong to USB bus which are created
> > dynamically do not contain device node.
> 
> I don't know what you mean.  struct usb_device _does_ contain an 
> embedded struct device.  It doesn't matter the structures are created 
> dynamically, statically, or any other way; this field is part of the 
> structure definition.
> 
> Suppose udev is a pointer to struct usb_device.  Then udev->dev is a
> struct device and udev->dev.of_node is a pointer to struct device_node.  
> You don't need to add a new udev->of_node field; just use
> udev->dev.of_node instead.
> 

Yes, you are right.

-- 

Best Regards,
Peter Chen



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