USB: ehci - fix timer regression (056761e5) · Commits · 戴 / test

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:

David 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:

Greg Kroah-Hartman <gregkh@suse.de>

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);
		}
		}

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