On Mon, 12 Nov 2012, Tejun Heo wrote:

On Fri, Nov 09, 2012 at 02:51:59PM +0800, Aaron Lu wrote:

quoted

A new interface to block disk events is added, this interface is
meant to eliminate a race between PM runtime callback and disk events
checking.

Suppose the following device tree:
device_sata_port  (the parent)
  device_ODD      (the child)

Weren't you gonna do something different about this?  I mean, if sr
knows that autopm kicked in, it can simply tell the block layer that
nothing is going on.  Wouldn't that be simpler?

It wouldn't work for non-ZP drives.  They do need to be polled, even 
when suspended.

Alan Stern