From stern@rowland.harvard.edu Thu Mar 15 15:37:40 2007 Date: Thu, 15 Mar 2007 15:54:30 -0400 (EDT) From: Alan Stern To: Greg KH cc: David Brownell , Alexey Fisher Subject: EHCI: add delay to bus_resume before accessing ports Message-ID: 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 Cc: David Brownell Signed-off-by: Greg Kroah-Hartman --- 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 @@ -136,6 +136,10 @@ static int ehci_bus_resume (struct usb_h /* 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--) {