tree 11355668006ea8d2c2ebbb25770d11a8d397cb5b
parent 6e018751a35f6ef7ad04eb8006b5886b6a7c47f5
author Alan Stern <stern@rowland.harvard.edu> 1363973518 -0400
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1364243792 -0700

USB: EHCI: improve end_unlink_async()

This patch (as1665) changes the way ehci-hcd's end_unlink_async()
routine works in order to avoid recursive execution and to be more
efficient:

	Now when an IAA cycle ends, a new one gets started up right
	away (if it is needed) instead of waiting until the
	just-unlinked QH has been processed.

	The async_iaa list is renamed to async_idle, which better
	expresses its new purpose: It is now the list of QHs which are
	now completely idle and are waiting to be processed by
	end_unlink_async().

	A new flag is added to track whether an IAA cycle is in
	progress, because the list formerly known as async_iaa no
	longer stores the QHs waiting for the IAA to finish.

	The decision about how many QHs to process when an IAA cycle
	ends is now made at the end of the cycle, when we know the
	current state of the hardware, rather than at the beginning.
	This means a bunch of logic got moved from start_iaa_cycle()
	to end_unlink_async().

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>