On 08/30/2012 04:28 PM, Alan Stern wrote:
On Thu, 30 Aug 2012, Sebastian Andrzej Siewior wrote:
So the problem appears to be that dummy-hcd doesn't implement the right
interval for periodic transfers. I'd accept a patch to fix that.
That is also missing. However, we are pulled down, that means
find_endpoint() in dummy returns always NULL due to !active(). So we
never get here to delay the interrupt packet.
You're missing the point. The test of the interrupt URB's interval
should be done _before_ find_endpoint() is called.
The endpoint has a last_io field which could be used for that (which
isn't used right now at all) so I though it would be handy to consider
that. However, for that we need the endpoint…
In that case I would have to extend urbp for by an last_io member.
That's how real host controllers work; they don't try to contact
interrupt endpoints during frames that aren't in the endpoint's
schedule.
Yes but they know to which endpoint the particular URB belongs. dummy
just wakes up and says "I have no memory of you" and completes it.
(The same goes for isochronous endpoints... but dummy-hcd currently
doesn't support isochronous at all.)
Alan Stern
Sebastian
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
