From 70c05e4cf63054cd755ca66c1819327b22cb085f Mon Sep 17 00:00:00 2001
From: Henry Lin <henryl@nvidia.com>
Date: Thu, 3 Mar 2022 13:08:58 +0200
Subject: [PATCH] xhci: fix runtime PM imbalance in USB2 resume
Git-commit: 70c05e4cf63054cd755ca66c1819327b22cb085f
Patch-mainline: v5.18-rc1
References: git-fixes

A race between system resume and device-initiated resume may result in
runtime PM imbalance on USB2 root hub. If a device-initiated resume
starts and system resume xhci_bus_resume() directs U0 before hub driver
sees the resuming device in RESUME state, device-initiated resume will
not be finished in xhci_handle_usb2_port_link_resume(). In this case,
usb_hcd_end_port_resume() call is missing.

This changes calls usb_hcd_end_port_resume() if resuming device reaches
U0 to keep runtime PM balance.

Fixes: a231ec41e6f6 ("xhci: refactor U0 link state handling in get_port_status")
Cc: stable@vger.kernel.org
Signed-off-by: Henry Lin <henryl@nvidia.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20220303110903.1662404-5-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, 3 insertions(+)

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index bb4f01ce90e3..1e7dc130c39a 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -1088,6 +1088,9 @@ static void xhci_get_usb2_port_status(struct xhci_port *port, u32 *status,
 		if (link_state == XDEV_U2)
 			*status |= USB_PORT_STAT_L1;
 		if (link_state == XDEV_U0) {
+			if (bus_state->resume_done[portnum])
+				usb_hcd_end_port_resume(&port->rhub->hcd->self,
+							portnum);
 			bus_state->resume_done[portnum] = 0;
 			clear_bit(portnum, &bus_state->resuming_ports);
 			if (bus_state->suspended_ports & (1 << portnum)) {
-- 
2.31.1