From dc92944a014cd6a6f6c94299aaa36164dd2c238a Mon Sep 17 00:00:00 2001
From: Henry Lin <henryl@nvidia.com>
Date: Fri, 8 Apr 2022 16:48:22 +0300
Subject: [PATCH] xhci: stop polling roothubs after shutdown
Git-commit: dc92944a014cd6a6f6c94299aaa36164dd2c238a
References: git-fixes
Patch-mainline: v5.18-rc5

While rebooting, XHCI controller and its bus device will be shut down
in order by .shutdown callback. Stopping roothubs polling in
xhci_shutdown() can prevent XHCI driver from accessing port status
after its bus device shutdown.

Take PCIe XHCI controller as example, if XHCI driver doesn't stop roothubs
polling, XHCI driver may access PCIe BAR register for port status after
parent PCIe root port driver is shutdown and cause PCIe bus error.

[check shared hcd exist before stopping its roothub polling -Mathias]

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/20220408134823.2527272-3-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/usb/host/xhci.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 642610c78f58..25b87e99b4dd 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -781,6 +781,17 @@ void xhci_shutdown(struct usb_hcd *hcd)
 	if (xhci->quirks & XHCI_SPURIOUS_REBOOT)
 		usb_disable_xhci_ports(to_pci_dev(hcd->self.sysdev));
 
+	/* Don't poll the roothubs after shutdown. */
+	xhci_dbg(xhci, "%s: stopping usb%d port polling.\n",
+			__func__, hcd->self.busnum);
+	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
+	del_timer_sync(&hcd->rh_timer);
+
+	if (xhci->shared_hcd) {
+		clear_bit(HCD_FLAG_POLL_RH, &xhci->shared_hcd->flags);
+		del_timer_sync(&xhci->shared_hcd->rh_timer);
+	}
+
 	spin_lock_irq(&xhci->lock);
 	xhci_halt(xhci);
 	/* Workaround for spurious wakeups at shutdown with HSW */
-- 
2.35.3