The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From bd82873f23c9a6ad834348f8b83f3b6a5bca2c65 Mon Sep 17 00:00:00 2001
From: Mathias Nyman mathias.nyman@linux.intel.com Date: Wed, 11 Dec 2019 16:20:07 +0200 Subject: [PATCH] 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: 8b3d45705e54 ("usb: Fix xHCI host issues on remote wakeup.") Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com Link: https://lore.kernel.org/r/20191211142007.8847-7-mathias.nyman@linux.intel.co... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c index 4b870cd6c575..7a3a29e5e9d2 100644 --- a/drivers/usb/host/xhci-hub.c +++ b/drivers/usb/host/xhci-hub.c @@ -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;