xhci: Do not halt the host until both HCD have disconnected their devices.

We can't halt the host controller immediately when first HCD is removed as
it will cause problems if we have devices attached to the second (primary)
HCD, like a keyboard.

We've been carrying this in our Linux-as-a-bootloader environment for a
little while now. The machines all have the same TI TUSB73x0 part,
and when we kexec the devices don't come back until a system power cycle.

[minor adjustments, code comments and remove HALT check  -Mathias]
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index e523dbd1ee4e83a1a0dc0a917eacaf0f3d5df4d1..5ecba7c85889e63cc8ef48375080fecae405619a 100644 (file)
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -692,21 +692,21 @@ void xhci_stop(struct usb_hcd *hcd)
 
        mutex_lock(&xhci->mutex);
 
-       if (!(xhci->xhc_state & XHCI_STATE_HALTED)) {
-               spin_lock_irq(&xhci->lock);
-
-               xhci->xhc_state |= XHCI_STATE_HALTED;
-               xhci->cmd_ring_state = CMD_RING_STATE_STOPPED;
-               xhci_halt(xhci);
-               xhci_reset(xhci);
-               spin_unlock_irq(&xhci->lock);
-       }
-
+       /* Only halt host and free memory after both hcds are removed */
        if (!usb_hcd_is_primary_hcd(hcd)) {
+               /* usb core will free this hcd shortly, unset pointer */
+               xhci->shared_hcd = NULL;
                mutex_unlock(&xhci->mutex);
                return;
        }
 
+       spin_lock_irq(&xhci->lock);
+       xhci->xhc_state |= XHCI_STATE_HALTED;
+       xhci->cmd_ring_state = CMD_RING_STATE_STOPPED;
+       xhci_halt(xhci);
+       xhci_reset(xhci);
+       spin_unlock_irq(&xhci->lock);
+
        xhci_cleanup_msix(xhci);
 
        /* Deleting Compliance Mode Recovery Timer */