Re: [PATCH 1/6] USB: remove __usb_port_suspend

On Wed, 30 May 2007, David Brownell wrote:

> On Wednesday 30 May 2007, Alan Stern wrote:
> > 
> > Propagating the change into the OTG HNP handler requires a slight
> > addition to the OTG whitelist checking code: A device not attached to
> > the OTG port should always count as "targeted".
> 
> No, that's not what the OTG spec says.  If there's a
> list of targeted peripherals ... that's it.  It applies
> to all host ports, not just the OTG port.
> 
> You need to revert that change.

I must have misunderstood something from our earlier conversation.

I thought you said that if a system has multiple USB ports, then one of
them can be an OTG port and the rest act like ordinary host ports.  
Hence a device plugged into one of the non-OTG ports should always
count as "targeted" in the sense that the system should always be
willing to treat it as a normal device and communicate with it.
Conversely, the test for whether or not a device really is targeted
should matter only when the device is plugged into the OTG port.

According to the original code, plugging a non-targeted device into 
a non-OTG port would cause the host to initiate HNP on the OTG port!  
At least, that's what it looks like to me.  Have I got it wrong?

Or is the patch in fact correct?

Alan Stern


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