@@ -1047,8 +1047,8 @@ static u32 xhci_get_port_status(struct usb_hcd *hcd,
xhci_get_usb2_port_status(port, &status, raw_port_status,
flags);
/*
- * Clear stale usb2 resume signalling variables in case port changed
- * state during resume signalling. For example on error
+ * Clear stale resume signalling variables in case port changed
+ * state during resume signalling. For example on error.
*/
if ((bus_state->resume_done[wIndex] ||
test_bit(wIndex, &bus_state->resuming_ports)) &&
@@ -1057,6 +1057,9 @@ static u32 xhci_get_port_status(struct usb_hcd *hcd,
bus_state->resume_done[wIndex] = 0;
clear_bit(wIndex, &bus_state->resuming_ports);
usb_hcd_end_port_resume(&hcd->self, wIndex);
+ } else if (bus_state->port_remote_wakeup & (1 << port->hcd_portnum) &&
+ !(raw_port_status & PORT_CONNECT)) {
+ bus_state->port_remote_wakeup &= ~(1 << port->hcd_portnum);
}
if (bus_state->port_c_suspend & (1 << wIndex))
This was seen on a Dell Precision 5520 using it's WD15 dock. The dock's Ethernet connectivity is provided though USB. While idle, both the Ethernet device and XHCI are suspended by runtime PM. To be then resumed on behalf of the Ethernet device, which has remote wake-up capabilities. The Ethernet device was observed to randomly disconnect from the USB port shortly after submitting it's remote wake-up request. Probably a weird timing issue yet to be investigated. This causes runtime PM to busyloop causing some tangible CPU load. The reason is the port gets stuck in the middle of a remote wake-up operation, waiting for the device to switch to U0. This never happens, leaving "port_remote_wakeup" enabled, and automatically triggering a failure on any further suspend operation. This patch clears "port_remote_wakeup" upon detecting a device with a wrong PORT_CONNECT state. Making sure the above mentioned situation doesn't trigger a PM busyloop. Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> --- Changes since v1: - Do not trigger clear based on PLS_MASK != XDEV_RESUME to avoid a potential race condition between the irq handler and hub thread. drivers/usb/host/xhci-hub.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)