[PATCH 2.6.21.3 1/1] ehci-hub: improved over-current recovery

From: Christian Engelmayer <[email protected]>

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 hubs
violate this requirement, but need port power to be cycled by
software in order to get back to normal functionality after an
over-current condition.

Signed-off-by: Christian Engelmayer <[email protected]>
Signed-off-by: David Brownell <[email protected]>

---
This fix was tested on an MPC8343E.

--- a/drivers/usb/host/ehci-hub.c.orig	2007-05-29 21:30:35.000000000 +0200
+++ b/drivers/usb/host/ehci-hub.c	2007-05-29 21:39:48.000000000 +0200
@@ -389,6 +389,20 @@ ehci_hub_status_data (struct usb_hcd *hc
 			    buf [1] |= 1 << (i - 7);
 			status = STS_PCD;
 		}
+
+		/*
+		 * The hub was supposed to disable port power autonomously
+		 * on over-current. However, not all hubs can be trusted to
+		 * do this although they need port power disabled in order
+		 * to recover properly.
+		 */
+		if (temp & PORT_OCC) {
+			if (HCS_PPC(ehci->hcs_params)){
+				temp &= ~(PORT_RWC_BITS | PORT_POWER);
+				writel (temp, &ehci->regs->port_status [i]);
+			}
+		}
+
 	}
 	/* FIXME autosuspend idle root hubs */
 	spin_unlock_irqrestore (&ehci->lock, flags);


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