[PATCH 5.6 154/167] xhci: prevent bus suspend if a roothub port detected a over-current condition

From: Greg Kroah-Hartman
Date: Tue Apr 28 2020 - 14:38:20 EST


From: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>

commit e9fb08d617bfae5471d902112667d0eeb9dee3c4 upstream.

Suspending the bus and host controller while a port is in a over-current
condition may halt the host.
Also keep the roothub running if over-current is active.

Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200421140822.28233-3-mathias.nyman@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/usb/host/xhci-hub.c | 9 +++++++++
1 file changed, 9 insertions(+)

--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -1569,6 +1569,8 @@ int xhci_hub_status_data(struct usb_hcd
}
if ((temp & PORT_RC))
reset_change = true;
+ if (temp & PORT_OC)
+ status = 1;
}
if (!status && !reset_change) {
xhci_dbg(xhci, "%s: stopping port polling.\n", __func__);
@@ -1634,6 +1636,13 @@ retry:
port_index);
goto retry;
}
+ /* bail out if port detected a over-current condition */
+ if (t1 & PORT_OC) {
+ bus_state->bus_suspended = 0;
+ spin_unlock_irqrestore(&xhci->lock, flags);
+ xhci_dbg(xhci, "Bus suspend bailout, port over-current detected\n");
+ return -EBUSY;
+ }
/* suspend ports in U0, or bail out for new connect changes */
if ((t1 & PORT_PE) && (t1 & PORT_PLS_MASK) == XDEV_U0) {
if ((t1 & PORT_CSC) && wake_enabled) {