4.9-stable review patch. If anyone has any objections, please let me know.
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From: Mathias Nyman mathias.nyman@linux.intel.com
commit 45f750c16cae3625014c14c77bd9005eda975d35 upstream.
The code to prevent a bus suspend if a USB3 port was still in link training also reacted to USB2 port polling state. This caused bus suspend to busyloop in some cases. USB2 polling state is different from USB3, and should not prevent bus suspend.
Limit the USB3 link training state check to USB3 root hub ports only. The origial commit went to stable so this need to be applied there as well
Fixes: 2f31a67f01a8 ("usb: xhci: Prevent bus suspend if a port connect change or polling state is detected") Cc: stable@vger.kernel.org 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 | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/usb/host/xhci-hub.c +++ b/drivers/usb/host/xhci-hub.c @@ -1353,7 +1353,8 @@ int xhci_bus_suspend(struct usb_hcd *hcd portsc_buf[port_index] = 0;
/* Bail out if a USB3 port has a new device in link training */ - if ((t1 & PORT_PLS_MASK) == XDEV_POLLING) { + if ((hcd->speed >= HCD_USB3) && + (t1 & PORT_PLS_MASK) == XDEV_POLLING) { bus_state->bus_suspended = 0; spin_unlock_irqrestore(&xhci->lock, flags); xhci_dbg(xhci, "Bus suspend bailout, port in polling\n");