From 45f750c16cae3625014c14c77bd9005eda975d35 Mon Sep 17 00:00:00 2001
From: Mathias Nyman <mathias.nyman@linux.intel.com>
Date: Fri, 14 Dec 2018 10:54:43 +0200
Subject: [PATCH] xhci: Don't prevent USB2 bus suspend in state check intended for USB3 only
Git-commit: 45f750c16cae3625014c14c77bd9005eda975d35
Patch-mainline: v4.20
References: bsc#1051510

The code to prevent a bus suspend if a USB3 port was still in link training
also reacted to USB2 port polling state.
This caused bus suspend to busyloop in some cases.
USB2 polling state is different from USB3, and should not prevent bus
suspend.

Limit the USB3 link training state check to USB3 root hub ports only.
The origial commit went to stable so this need to be applied there as well

Fixes: 2f31a67f01a8 ("usb: xhci: Prevent bus suspend if a port connect change or polling state is detected")
Cc: stable@vger.kernel.org
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 | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index 94aca1b5ac8a..01b5818a4be5 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -1507,7 +1507,8 @@ int xhci_bus_suspend(struct usb_hcd *hcd)
 		portsc_buf[port_index] = 0;
 
 		/* Bail out if a USB3 port has a new device in link training */
-		if ((t1 & PORT_PLS_MASK) == XDEV_POLLING) {
+		if ((hcd->speed >= HCD_USB3) &&
+		    (t1 & PORT_PLS_MASK) == XDEV_POLLING) {
 			bus_state->bus_suspended = 0;
 			spin_unlock_irqrestore(&xhci->lock, flags);
 			xhci_dbg(xhci, "Bus suspend bailout, port in polling\n");
-- 
2.19.2