From 958c0bd86075d4ef1c936998deefe1947e539240 Mon Sep 17 00:00:00 2001
From: Aaron Ma <aaron.ma@canonical.com>
Date: Fri, 9 Nov 2018 17:21:20 +0200
Subject: [PATCH] usb: xhci: fix uninitialized completion when USB3 port got wrong status
Git-commit: 958c0bd86075d4ef1c936998deefe1947e539240
Patch-mainline: v4.20-rc4
References: bsc#1051510

Realtek USB3.0 Card Reader [0bda:0328] reports wrong port status on
Cannon lake PCH USB3.1 xHCI [8086:a36d] after resume from S3,
after clear port reset it works fine.

Since this device is registered on USB3 roothub at boot,
when port status reports not superspeed, xhci_get_port_status will call
an uninitialized completion in bus_state[0].
Kernel will hang because of NULL pointer.

Restrict the USB2 resume status check in USB2 roothub to fix hang issue.

Cc: stable@vger.kernel.org
Signed-off-by: Aaron Ma <aaron.ma@canonical.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/usb/host/xhci-hub.c  |    2 +-
 drivers/usb/host/xhci-ring.c |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -885,7 +885,7 @@ static u32 xhci_get_port_status(struct u
 			status |= USB_PORT_STAT_SUSPEND;
 	}
 	if ((raw_port_status & PORT_PLS_MASK) == XDEV_RESUME &&
-		!DEV_SUPERSPEED_ANY(raw_port_status)) {
+		!DEV_SUPERSPEED_ANY(raw_port_status) && hcd->speed < HCD_USB3) {
 		if ((raw_port_status & PORT_RESET) ||
 				!(raw_port_status & PORT_PE))
 			return 0xffffffff;
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1717,7 +1717,7 @@ static void handle_port_status(struct xh
 	 * RExit to a disconnect state).  If so, let the the driver know it's
 	 * out of the RExit state.
 	 */
-	if (!DEV_SUPERSPEED_ANY(portsc) &&
+	if (!DEV_SUPERSPEED_ANY(portsc) && hcd->speed < HCD_USB3 &&
 			test_and_clear_bit(faked_port_index,
 				&bus_state->rexit_ports)) {
 		complete(&bus_state->rexit_done[faked_port_index]);