[PATCH 3.16 028/136] xhci: Prevent device initiated U1/U2 link pm if exit latency is too long

[Ben Hutchings]

3.16.80-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>

commit cd9d9491e835a845c1a98b8471f88d26285e0bb9 upstream.

If host/hub initiated link pm is prevented by a driver flag we still must
ensure that periodic endpoints have longer service intervals than link pm
exit latency before allowing device initiated link pm.

Fix this by continue walking and checking endpoint service interval if
xhci_get_timeout_no_hub_lpm() returns anything else than USB3_LPM_DISABLED

While at it fix the split line error message

Tested-by: Jan Schmidt <jan@xxxxxxxxxxxxxxx>
Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/1570190373-30684-3-git-send-email-mathias.nyman@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/usb/host/xhci.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -4618,10 +4618,12 @@ static u16 xhci_calculate_lpm_timeout(st
 		if (intf->dev.driver) {
 			driver = to_usb_driver(intf->dev.driver);
 			if (driver && driver->disable_hub_initiated_lpm) {
-				dev_dbg(&udev->dev, "Hub-initiated %s disabled "
-						"at request of driver %s\n",
-						state_name, driver->name);
-				return xhci_get_timeout_no_hub_lpm(udev, state);
+				dev_dbg(&udev->dev, "Hub-initiated %s disabled at request of driver %s\n",
+					state_name, driver->name);
+				timeout = xhci_get_timeout_no_hub_lpm(udev,
+								      state);
+				if (timeout == USB3_LPM_DISABLED)
+					return timeout;
 			}
 		}