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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>
Alan Stern 18 жил өмнө
parent
commit
e198a31489

+ 4 - 0
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 */
 	/* restore CMD_RUN, framelist size, and irq threshold */
 	ehci_writel(ehci, ehci->command, &ehci->regs->command);
 	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() */
 	/* manually resume the ports we suspended during bus_suspend() */
 	i = HCS_N_PORTS (ehci->hcs_params);
 	i = HCS_N_PORTS (ehci->hcs_params);
 	while (i--) {
 	while (i--) {