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

[Alan Stern]

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.

Alan Stern

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