Re: [linux-usb-devel] ehci calling put_device from irq handler

[Greg KH <greg@kroah.com>]

On Wed, Jan 18, 2006 at 04:54:04PM -0500, Alan Stern wrote:
> On Wed, 18 Jan 2006, Greg KH wrote:
> 
> > We can not call put_device() from irq context :(
> > 
> > I added a "might_sleep()" to the driver core and get the following from
> > the ehci driver.  Any thoughts?
> 
> In principle the put_device and corresponding get_device calls aren't
> needed.  We don't release a usb_device structure until after disabling all
> its endpoints, and disabling an endpoint will wait until all the URBs for
> that endpoint have completed.  So there's no reason to keep a reference to
> the device structure for each URB.
> 
> I see that uhci-hcd is guilty of the same thing (reference acquired for 
> each QH, released while holding a spinlock).  Probably each of the 
> host controller drivers is.

Great, care to make up a patch to fix this?

:)

thanks,

greg k-h