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Message-Id: <20220405070340.839223799@linuxfoundation.org>
Date: Tue, 5 Apr 2022 09:18:16 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org, Henry Lin <henryl@...dia.com>,
Mathias Nyman <mathias.nyman@...ux.intel.com>
Subject: [PATCH 5.15 034/913] xhci: fix runtime PM imbalance in USB2 resume
From: Henry Lin <henryl@...dia.com>
commit 70c05e4cf63054cd755ca66c1819327b22cb085f upstream.
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@...r.kernel.org
Signed-off-by: Henry Lin <henryl@...dia.com>
Signed-off-by: Mathias Nyman <mathias.nyman@...ux.intel.com>
Link: https://lore.kernel.org/r/20220303110903.1662404-5-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
drivers/usb/host/xhci-hub.c | 3 +++
1 file changed, 3 insertions(+)
--- 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(st
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)) {
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