From 98cae42d82fe9c9e2b5dacdf391edaa007e147e5 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Fri, 28 Sep 2012 16:01:34 -0400 Subject: EHCI: use the isochronous scheduling threshold This patch (as1609) changes the way ehci-hcd uses the "Isochronous Scheduling Threshold" in its calculations. Until now the code has ignored the threshold except for certain Intel PCI-based controllers. This violates the EHCI spec. The new code takes the threshold into account always, removing the need for the fs_i_thresh quirk flag. In addition it implements the "full frame cache" setting more efficiently, moving forward only as far as the next frame boundary instead of always moving forward 8 microframes. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/ehci-sched.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) (limited to 'drivers/usb/host/ehci-sched.c') diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c index 7eb242f27c00..b764cab2ab9a 100644 --- a/drivers/usb/host/ehci-sched.c +++ b/drivers/usb/host/ehci-sched.c @@ -1391,15 +1391,11 @@ iso_stream_schedule ( */ if (likely (!list_empty (&stream->td_list))) { - /* For high speed devices, allow scheduling within the - * isochronous scheduling threshold. For full speed devices - * and Intel PCI-based controllers, don't (work around for - * Intel ICH9 bug). - */ - if (!stream->highspeed && ehci->fs_i_thresh) - next = now + ehci->i_thresh; + /* Take the isochronous scheduling threshold into account */ + if (ehci->i_thresh) + next = now + ehci->i_thresh; /* uframe cache */ else - next = now; + next = (now + 2 + 7) & ~0x07; /* full frame cache */ /* * Use ehci->last_iso_frame as the base. There can't be any -- cgit v1.2.1