[linux-usb-devel] [PATCH 1/3] UEAGLE : be suspend friendly

Alan Stern stern at rowland.harvard.edu
Fri Oct 6 14:20:42 EDT 2006

On Fri, 6 Oct 2006, Duncan Sands wrote:

> > Maybe UEAGLE can do something a little more sensible...
> What is the modem supposed to do if it receives a packet to
> transmit after it has been told to suspend?  This is a real
> question, I'm not pretending!  I've never thought about or
> read about suspend/resume and have no idea how it is supposed
> to work.  Should it just reject it, or should it wake the
> modem up?

It depends on the context in which the modem was suspended.  If this was a 
regular system sleep transition, or some other suspend request coming from 
outside the driver, then packets should be dropped.

But if the suspend originated within the driver itself, as a power-saving 
measure while the connection was idle, then new packets should cause the 
driver to wake the modem up.  That is, self-originated suspends should be 
transparent.  Outside-originated suspends are someone else's problem.

Alan Stern

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