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: Christian Engelmayer <christian.engelmayer@frequentis.com>
Signed-off-by: David Brownell <david-b@pacbell.net>
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 27291f50..71aeca0 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -647,9 +647,24 @@
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) {