Commit c22fa3ac authored Jun 13, 2005 by David Brownell Committed by Linus Torvalds Jun 13, 2005

[PATCH] spin longer for ehci port reset completion

This makes the EHCI driver spin a bit longer before concluding that the
port reset failed. "Obviously safe."

It allows some devices to enumerate that previously didn't. We've seen
a bunch of these problem reports recently, this will make some go away.

As reported by Michael Zapf <Michael.Zapf@uni-kassel.de>, some EHCI
controllers seem to take forever to finish port resets and produce
"port N reset error -110" type errors. Spinning a bit longer helps.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

parent c0105338

drivers/usb/host/ehci-hub.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -439,9 +439,12 @@ static int ehci_hub_control (
		/* force reset to complete */
		writel (temp & ~PORT_RESET,
		&ehci->regs->port_status [wIndex]);
		/* REVISIT: some hardware needs 550+ usec to clear
		* this bit; seems too long to spin routinely...
		*/
		retval = handshake (
		&ehci->regs->port_status [wIndex],
		PORT_RESET, 0, 500);
		PORT_RESET, 0, 750);
		if (retval != 0) {
		ehci_err (ehci, "port %d reset error %d\n",
		wIndex + 1, retval);