From d58b4bcc6df8046cf9c3c59f9ff84d2cd86b93eb Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Wed, 11 Jul 2012 11:21:54 -0400 Subject: [PATCH] USB: EHCI: introduce high-res timer This patch (as1572) begins the conversion of ehci-hcd over to using high-resolution timers rather than old-fashioned low-resolution kernel timers. This reduces overhead caused by timer roundoff on systems where HZ is smaller than 1000. Also, the new timer framework introduced here is much more logical and easily extended than the ad-hoc approach ehci-hcd currently uses for timers. An hrtimer structure is added to ehci_hcd, along with a bitflag array and an array of ktime_t values, to keep track of which timing events are pending and what their expiration times are. Only the infrastructure for the timing operations is added in this patch. Later patches will add routines for handling each of the various timing events the driver needs. In some cases the new hrtimer handlers will replace the existing handlers for ehci-hcd's kernel timers; as this happens the old timers will be removed. In other cases the new timing events will replace busy-wait loops. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- Reading git-format-patch failed