Commit aa16ca30 authored by David Brownell's avatar David Brownell Committed by Greg Kroah-Hartman
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USB: ehci: minor ISO updates, always support split ISO 



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: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 3b6fcfd0

drivers/usb/host/Kconfig

+0 −9
Original line number Diff line number Diff line
@@ -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

drivers/usb/host/ehci-sched.c

+12 −35
Original line number Diff line number Diff line
@@ -1630,16 +1630,12 @@ 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);

	retval = true;

	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))) {
@@ -1725,8 +1721,6 @@ done: 
	return status;

}



#ifdef CONFIG_USB_EHCI_SPLIT_ISO



/*-------------------------------------------------------------------------*/



/*
@@ -2016,16 +2010,12 @@ 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);

	retval = true;

	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)) {
@@ -2108,26 +2098,6 @@ 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
@@ -2252,8 +2222,14 @@ restart: 
			}



			/* assume completion callbacks modify the queue */

			if (unlikely (modified))

			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 */
@@ -2269,7 +2245,8 @@ 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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