3.16.83-rc1 review patch. If anyone has any objections, please let me know.
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From: Mathias Nyman mathias.nyman@linux.intel.com
commit bd82873f23c9a6ad834348f8b83f3b6a5bca2c65 upstream.
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.
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 Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/usb/host/xhci-hub.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/drivers/usb/host/xhci-hub.c +++ b/drivers/usb/host/xhci-hub.c @@ -580,7 +580,7 @@ static u32 xhci_get_port_status(struct u struct xhci_bus_state *bus_state, __le32 __iomem **port_array, u16 wIndex, u32 raw_port_status, - unsigned long flags) + unsigned long *flags) __releases(&xhci->lock) __acquires(&xhci->lock) { @@ -670,12 +670,12 @@ static u32 xhci_get_port_status(struct u xhci_set_link_state(xhci, port_array, wIndex, 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, @@ -834,7 +834,7 @@ int xhci_hub_control(struct usb_hcd *hcd break; } status = xhci_get_port_status(hcd, bus_state, port_array, - wIndex, temp, flags); + wIndex, temp, &flags); if (status == 0xffffffff) goto error;