EHCI: add delay to bus_resume before accessing ports

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@rowland.harvard.edu>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index 1813b7cac294..f4d301bc83b9 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -136,6 +136,10 @@ static int ehci_bus_resume (struct usb_hcd *hcd)
         /* restore CMD_RUN, framelist size, and irq threshold */
         ehci_writel(ehci, 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--) {