USB: EHCI: simplify isochronous scanning

This patch (as1587) simplifies ehci-hcd's scan_isoc() routine by
eliminating some local variables, declaring boolean-valued values as
bool rather than unsigned, changing variable names to make more sense,
and so on.

The logic at the end of the routine is cut down significantly.  The
scanning doesn't have to catch up all the way to where the hardware
is; it merely has to catch up to where the hardware was when the last
interrupt occurred.  If the hardware has made more progress since then
and issued another interrupt, a rescan will catch up to it.

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

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index 254f414bd0bd..7de58fe52d51 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -141,19 +141,19 @@ struct ehci_hcd {			/* one per controller */
         struct ehci_qh          *intr_unlink;
         struct ehci_qh          *intr_unlink_last;
         unsigned                intr_unlink_cycle;
-        int                     next_uframe;    /* scan periodic, start here */
+        unsigned                now_frame;      /* frame from HC hardware */
+        unsigned                next_frame;     /* scan periodic, start here */
         unsigned                intr_count;     /* intr activity count */
         unsigned                isoc_count;     /* isoc activity count */
         unsigned                periodic_count; /* periodic activity count */
         unsigned                uframe_periodic_max; /* max periodic time per uframe */
 
 
-        /* list of itds & sitds completed while clock_frame was still active */
+        /* list of itds & sitds completed while now_frame was still active */
         struct list_head        cached_itd_list;
         struct ehci_itd         *last_itd_to_free;
         struct list_head        cached_sitd_list;
         struct ehci_sitd        *last_sitd_to_free;
-        unsigned                clock_frame;
 
         /* per root hub port */
         unsigned long           reset_done [EHCI_MAX_ROOT_PORTS];