Small updates to the EHCI driver's ISO support:
- Get rid of the Kconfig option for full speed ISO. It may
not be perfect yet, but it hasn't appeared to be dangerous
and pretty much every configuration wants it.
- Instead of two places to disable an empty periodic schedule
after an ISO transfer completes, just have one.
- After the periodic schedule is disabled, we can short-circuit
the schedule scan ... it can't possibly have more work to do.
Assuming a typical config with split iso enabled, the only change
in behavior should be almost unobservable: quicker termination
of periodic scans when the schedule gets emptied.
Signed-off-by: David Brownell <[EMAIL PROTECTED]>
---
drivers/usb/host/Kconfig | 9 --------
drivers/usb/host/ehci-sched.c | 47 ++++++++++--------------------------------
2 files changed, 12 insertions(+), 44 deletions(-)
--- g26.orig/drivers/usb/host/Kconfig 2007-12-30 23:12:01.000000000 -0800
+++ g26/drivers/usb/host/Kconfig 2007-12-30 23:12:20.000000000 -0800
@@ -29,15 +29,6 @@ config USB_EHCI_HCD
To compile this driver as a module, choose M here: the
module will be called ehci-hcd.
-config USB_EHCI_SPLIT_ISO
- bool "Full speed ISO transactions (EXPERIMENTAL)"
- depends on USB_EHCI_HCD && EXPERIMENTAL
- default n
- ---help---
- This code is new and hasn't been used with many different
- EHCI or USB 2.0 transaction translator implementations.
- It should work for ISO-OUT transfers, like audio.
-
config USB_EHCI_ROOT_HUB_TT
bool "Root Hub Transaction Translators (EXPERIMENTAL)"
depends on USB_EHCI_HCD && EXPERIMENTAL
--- g26.orig/drivers/usb/host/ehci-sched.c 2007-12-30 23:11:25.000000000
-0800
+++ g26/drivers/usb/host/ehci-sched.c 2007-12-30 23:23:06.000000000 -0800
@@ -1625,15 +1625,11 @@ itd_complete (
BUG_ON (itd->urb == urb);
*/
- /* give urb back to the driver ... can be out-of-order */
+ /* give urb back to the driver; completion often (re)submits */
dev = urb->dev;
ehci_urb_done(ehci, urb, 0);
urb = NULL;
-
- /* defer stopping schedule; completion can submit */
ehci->periodic_sched--;
- if (unlikely (!ehci->periodic_sched))
- (void) disable_periodic (ehci);
ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs--;
if (unlikely (list_empty (&stream->td_list))) {
@@ -1712,8 +1708,6 @@ done:
return status;
}
-#ifdef CONFIG_USB_EHCI_SPLIT_ISO
-
/*-------------------------------------------------------------------------*/
/*
@@ -1998,15 +1992,11 @@ sitd_complete (
BUG_ON (sitd->urb == urb);
*/
- /* give urb back to the driver */
+ /* give urb back to the driver; completion often (re)submits */
dev = urb->dev;
ehci_urb_done(ehci, urb, 0);
urb = NULL;
-
- /* defer stopping schedule; completion can submit */
ehci->periodic_sched--;
- if (!ehci->periodic_sched)
- (void) disable_periodic (ehci);
ehci_to_hcd(ehci)->self.bandwidth_isoc_reqs--;
if (list_empty (&stream->td_list)) {
@@ -2082,26 +2072,6 @@ done:
return status;
}
-#else
-
-static inline int
-sitd_submit (struct ehci_hcd *ehci, struct urb *urb, gfp_t mem_flags)
-{
- ehci_dbg (ehci, "split iso support is disabled\n");
- return -ENOSYS;
-}
-
-static inline unsigned
-sitd_complete (
- struct ehci_hcd *ehci,
- struct ehci_sitd *sitd
-) {
- ehci_err (ehci, "sitd_complete %p?\n", sitd);
- return 0;
-}
-
-#endif /* USB_EHCI_SPLIT_ISO */
-
/*-------------------------------------------------------------------------*/
static void
@@ -2238,8 +2208,14 @@ restart:
}
/* assume completion callbacks modify the queue */
- if (unlikely (modified))
- goto restart;
+ if (unlikely (modified)) {
+ if (likely(ehci->periodic_sched > 0))
+ goto restart;
+ /* maybe we can short-circuit this scan! */
+ disable_periodic(ehci);
+ now_uframe = clock;
+ break;
+ }
}
/* stop when we catch up to the HC */
@@ -2255,7 +2231,8 @@ restart:
if (now_uframe == clock) {
unsigned now;
- if (!HC_IS_RUNNING (ehci_to_hcd(ehci)->state))
+ if (!HC_IS_RUNNING (ehci_to_hcd(ehci)->state)
+ || ehci->periodic_sched == 0)
break;
ehci->next_uframe = now_uframe;
now = ehci_readl(ehci, &ehci->regs->frame_index) % mod;
-
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