4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Aaron Ma aaron.ma@canonical.com
commit 958c0bd86075d4ef1c936998deefe1947e539240 upstream.
Realtek USB3.0 Card Reader [0bda:0328] reports wrong port status on Cannon lake PCH USB3.1 xHCI [8086:a36d] after resume from S3, after clear port reset it works fine.
Since this device is registered on USB3 roothub at boot, when port status reports not superspeed, xhci_get_port_status will call an uninitialized completion in bus_state[0]. Kernel will hang because of NULL pointer.
Restrict the USB2 resume status check in USB2 roothub to fix hang issue.
Cc: stable@vger.kernel.org Signed-off-by: Aaron Ma aaron.ma@canonical.com Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/usb/host/xhci-hub.c | 2 +- drivers/usb/host/xhci-ring.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/usb/host/xhci-hub.c +++ b/drivers/usb/host/xhci-hub.c @@ -744,7 +744,7 @@ static u32 xhci_get_port_status(struct u status |= USB_PORT_STAT_SUSPEND; } if ((raw_port_status & PORT_PLS_MASK) == XDEV_RESUME && - !DEV_SUPERSPEED_ANY(raw_port_status)) { + !DEV_SUPERSPEED_ANY(raw_port_status) && hcd->speed < HCD_USB3) { if ((raw_port_status & PORT_RESET) || !(raw_port_status & PORT_PE)) return 0xffffffff; --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -1673,7 +1673,7 @@ static void handle_port_status(struct xh * RExit to a disconnect state). If so, let the the driver know it's * out of the RExit state. */ - if (!DEV_SUPERSPEED_ANY(temp) && + if (!DEV_SUPERSPEED_ANY(temp) && hcd->speed < HCD_USB3 && test_and_clear_bit(faked_port_index, &bus_state->rexit_ports)) { complete(&bus_state->rexit_done[faked_port_index]);