[patch 10/31] EHCI: add delay to bus_resume before accessing ports

[Greg KH]

-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>

This patch (as870) adds a delay to ehci-hcd's bus_resume routine.
Apparently there are controllers and/or BIOSes out there which need
such a delay to get the ports back into their correct state.  This
fixes Bugzilla #8190.

Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 drivers/usb/host/ehci-hub.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -134,6 +134,10 @@ static int ehci_bus_resume (struct usb_h
 	/* restore CMD_RUN, framelist size, and irq threshold */
 	writel (ehci->command, &ehci->regs->command);
 
+	/* Some controller/firmware combinations need a delay during which
+	 * they set up the port statuses.  See Bugzilla #8190. */
+	mdelay(8);
+
 	/* manually resume the ports we suspended during bus_suspend() */
 	i = HCS_N_PORTS (ehci->hcs_params);
 	while (i--) {

-- 
-
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