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 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 <[EMAIL PROTECTED]>
Signed-off-by: David Brownell <[EMAIL PROTECTED]>
Signed-off-by: Greg Kroah-Hartman <[EMAIL PROTECTED]>
---
Reason for updating this patch: I think I made a mistake doing
the change in ehci_hub_status_data() and I think that should be
better done in ehci_hub_control().
Forcing port power down a bit later when the hub driver retrieves
the port status information has got the advantage that it also
catches the case when an OC fault occurs during booting up the
board. Doing it in ehci_hub_status_data() bears the risk that the
OCC is not recognized as it was already acked by the hub code
when scanning ports at initialization and it would need a second
OCC to get back to live by chance.
--- a/drivers/usb/host/ehci-hub.c.orig 2007-06-08 15:33:16.000000000 +0200
+++ b/drivers/usb/host/ehci-hub.c 2007-06-08 18:35:20.000000000 +0200
@@ -552,8 +552,23 @@ 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) {
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