xhci: prevent bus_suspend if SS port resuming in phase 1

When the link is just waken, it's in Resume state, and driver sets PLS to
U0. This refers to Phase 1. Phase 2 refers to when the link has completed
the transition from Resume state to U0.

With the fix of xhci: report U3 when link is in resume state, it also
exposes an issue that usb3 roothub and controller can suspend right
after phase 1, and this causes a hard hang in controller.

To fix the issue, we need to prevent usb3 bus suspend if any port is
resuming in phase 1.

[merge separate USB2 and USB3 port resume checking to one -Mathias]
Cc: <stable@vger.kernel.org>
Signed-off-by: Zhuang Jin Can <jin.can.zhuang@intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 7 insertions, 3 deletions

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index 7df8878cc37b..fdca8edc5836 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -1123,10 +1123,10 @@ int xhci_bus_suspend(struct usb_hcd *hcd)
         spin_lock_irqsave(&xhci->lock, flags);
 
         if (hcd->self.root_hub->do_remote_wakeup) {
-                if (bus_state->resuming_ports) {
+                if (bus_state->resuming_ports ||        /* USB2 */
+                    bus_state->port_remote_wakeup) {    /* USB3 */
                         spin_unlock_irqrestore(&xhci->lock, flags);
-                        xhci_dbg(xhci, "suspend failed because "
-                                                "a port is resuming\n");
+                        xhci_dbg(xhci, "suspend failed because a port is resuming\n");
                         return -EBUSY;
                 }
         }
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 94416ff70810..6a8fc52aed58 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1546,6 +1546,9 @@ static void handle_port_status(struct xhci_hcd *xhci,
                 usb_hcd_resume_root_hub(hcd);
         }
 
+        if (hcd->speed == HCD_USB3 && (temp & PORT_PLS_MASK) == XDEV_INACTIVE)
+                bus_state->port_remote_wakeup &= ~(1 << faked_port_index);
+
         if ((temp & PORT_PLC) && (temp & PORT_PLS_MASK) == XDEV_RESUME) {
                 xhci_dbg(xhci, "port resume event for port %d\n", port_id);
 
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 31e46cc55807..ed2ebf647c38 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -285,6 +285,7 @@ struct xhci_op_regs {
 #define XDEV_U0         (0x0 << 5)
 #define XDEV_U2         (0x2 << 5)
 #define XDEV_U3         (0x3 << 5)
+#define XDEV_INACTIVE   (0x6 << 5)
 #define XDEV_RESUME     (0xf << 5)
 /* true: port has power (see HCC_PPC) */
 #define PORT_POWER      (1 << 9)