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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index bfe5f307cba68b6acfe5c28112bc095159f435bd..2d36a8deb2e61c9389c99d0b50f91825f9250ed6 100644 (file)
--- 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_hcd *hcd)
        /* 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--) {