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Commit 756aa6b3 authored by Christian Engelmayer's avatar Christian Engelmayer Committed by Greg Kroah-Hartman
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ehci-hub: improved over-current recovery 



According to the USB Specification Revision 2.0 chapter 11.12.5
a hub experiencing an over-current condition must place all
affected ports in the powered-off state. It seems that some root
hubs need port power to be cycled by software in order to get back
to normal functionality after an over-current condition ... like
the EHCI implementation on an MPC8343E.

Signed-off-by: default avatarChristian Engelmayer <christian.engelmayer@frequentis.com>
Signed-off-by: default avatarDavid Brownell <david-b@pacbell.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 648dcfc8

drivers/usb/host/ehci-hub.c

+16 −1
Original line number Diff line number Diff line
@@ -647,9 +647,24 @@ static int ehci_hub_control ( 
			status |= 1 << USB_PORT_FEAT_C_CONNECTION;

		if (temp & PORT_PEC)

			status |= 1 << USB_PORT_FEAT_C_ENABLE;

		if ((temp & PORT_OCC) && !ignore_oc)



		if ((temp & PORT_OCC) && !ignore_oc){

			status |= 1 << USB_PORT_FEAT_C_OVER_CURRENT;



			/*

			 * Hubs should disable port power on over-current.

			 * However, not all EHCI implementations do this

			 * automatically, even if they _do_ support per-port

			 * power switching; they're allowed to just limit the

			 * current.  khubd will turn the power back on.

			 */

			if (HCS_PPC (ehci->hcs_params)){

				ehci_writel(ehci,

					temp & ~(PORT_RWC_BITS | PORT_POWER),

					status_reg);

			}

		}



		/* whoever resumes must GetPortStatus to complete it!! */

		if (temp & PORT_RESUME) {