Commit bd82873f authored by Mathias Nyman's avatar Mathias Nyman Committed by Greg Kroah-Hartman
Browse files

xhci: make sure interrupts are restored to correct state 



spin_unlock_irqrestore() might be called with stale flags after
reading port status, possibly restoring interrupts to a incorrect
state.

If a usb2 port just finished resuming while the port status is read
the spin lock will be temporary released and re-acquired in a separate
function. The flags parameter is passed as value instead of a pointer,
not updating flags properly before the final spin_unlock_irqrestore()
is called.

Cc: <stable@vger.kernel.org> # v3.12+
Fixes: 8b3d4570 ("usb: Fix xHCI host issues on remote wakeup.")
Signed-off-by: default avatarMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20191211142007.8847-7-mathias.nyman@linux.intel.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 7ff11162

drivers/usb/host/xhci-hub.c

+6 −6
Original line number Diff line number Diff line
@@ -806,7 +806,7 @@ static void xhci_del_comp_mod_timer(struct xhci_hcd *xhci, u32 status, 


static int xhci_handle_usb2_port_link_resume(struct xhci_port *port,

					     u32 *status, u32 portsc,

					     unsigned long flags)

					     unsigned long *flags)

{

	struct xhci_bus_state *bus_state;

	struct xhci_hcd	*xhci;
@@ -860,11 +860,11 @@ static int xhci_handle_usb2_port_link_resume(struct xhci_port *port, 
		xhci_test_and_clear_bit(xhci, port, PORT_PLC);

		xhci_set_link_state(xhci, port, XDEV_U0);



		spin_unlock_irqrestore(&xhci->lock, flags);

		spin_unlock_irqrestore(&xhci->lock, *flags);

		time_left = wait_for_completion_timeout(

			&bus_state->rexit_done[wIndex],

			msecs_to_jiffies(XHCI_MAX_REXIT_TIMEOUT_MS));

		spin_lock_irqsave(&xhci->lock, flags);

		spin_lock_irqsave(&xhci->lock, *flags);



		if (time_left) {

			slot_id = xhci_find_slot_id_by_port(hcd, xhci,
@@ -967,7 +967,7 @@ static void xhci_get_usb3_port_status(struct xhci_port *port, u32 *status, 
}



static void xhci_get_usb2_port_status(struct xhci_port *port, u32 *status,

				      u32 portsc, unsigned long flags)

				      u32 portsc, unsigned long *flags)

{

	struct xhci_bus_state *bus_state;

	u32 link_state;
@@ -1017,7 +1017,7 @@ static void xhci_get_usb2_port_status(struct xhci_port *port, u32 *status, 
static u32 xhci_get_port_status(struct usb_hcd *hcd,

		struct xhci_bus_state *bus_state,

	u16 wIndex, u32 raw_port_status,

		unsigned long flags)

		unsigned long *flags)

	__releases(&xhci->lock)

	__acquires(&xhci->lock)

{
@@ -1140,7 +1140,7 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, 
		}

		trace_xhci_get_port_status(wIndex, temp);

		status = xhci_get_port_status(hcd, bus_state, wIndex, temp,

					      flags);

					      &flags);

		if (status == 0xffffffff)

			goto error;

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