Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 056761e5 authored by David Brownell's avatar David Brownell Committed by Greg Kroah-Hartman
Browse files

USB: ehci - fix timer regression 



This patch fixes a regression in the EHCI driver's TIMER_IO_WATCHDOG
behavior.  The patch "USB: EHCI: add separate IAA watchdog timer" changed
how that timer is handled, so that short timeouts on the remaining
timer (unfortunately, overloaded) would never be used.

This takes a more direct approach, reorganizing the code slightly to
be explicit about only the I/O watchdog role now being overridable.
It also replaces a now-obsolete comment describing older timer behavior.

Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Leonid <leonidv11@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 4b828abe

drivers/usb/host/ehci.h

+10 −9
Original line number Diff line number Diff line
@@ -177,6 +177,15 @@ timer_action_done (struct ehci_hcd *ehci, enum ehci_timer_action action) 
static inline void

timer_action (struct ehci_hcd *ehci, enum ehci_timer_action action)

{

	/* Don't override timeouts which shrink or (later) disable

	 * the async ring; just the I/O watchdog.  Note that if a

	 * SHRINK were pending, OFF would never be requested.

	 */

	if (timer_pending(&ehci->watchdog)

			&& ((BIT(TIMER_ASYNC_SHRINK) | BIT(TIMER_ASYNC_OFF))

				& ehci->actions))

		return;



	if (!test_and_set_bit (action, &ehci->actions)) {

		unsigned long t;
@@ -192,15 +201,7 @@ timer_action (struct ehci_hcd *ehci, enum ehci_timer_action action) 
			t = EHCI_SHRINK_JIFFIES;

			break;

		}

		t += jiffies;

		// all timings except IAA watchdog can be overridden.

		// async queue SHRINK often precedes IAA.  while it's ready

		// to go OFF neither can matter, and afterwards the IO

		// watchdog stops unless there's still periodic traffic.

		if (time_before_eq(t, ehci->watchdog.expires)

				&& timer_pending (&ehci->watchdog))

			return;

		mod_timer (&ehci->watchdog, t);

		mod_timer(&ehci->watchdog, t + jiffies);

	}

}