[PATCH 4.4 15/48] xhci: Dont print a warning when setting link state for disabled ports

Greg Kroah-Hartman
2018-10-18T18:05:12Z

From: Mathias Nyman <mathias.nyman@linux.intel.com>

commit 1208d8a84fdcae6b395c57911cdf907450d30e70 upstream.

When disabling a USB3 port the hub driver will set the port link state to
U3 to prevent "ejected" or "safely removed" devices that are still
physically connected from immediately re-enumerating.

If the device was really unplugged, then error messages were printed
as the hub tries to set the U3 link state for a port that is no longer
enabled.

xhci-hcd ee000000.usb: Cannot set link state.
usb usb8-port1: cannot disable (err = -32)

Don't print error message in xhci-hub if hub tries to set port link state
for a disabled port. Return -ENODEV instead which also silences hub driver.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Tested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Ross Zwisler <zwisler@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/usb/host/xhci-hub.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)

--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -1048,17 +1048,17 @@ int xhci_hub_control(struct usb_hcd *hcd
temp = readl(port_array[wIndex]);
break;
}
-
- /* Software should not attempt to set
- * port link state above '3' (U3) and the port
- * must be enabled.
- */
- if ((temp & PORT_PE) == 0 ||
- (link_state > USB_SS_PORT_LS_U3)) {
- xhci_warn(xhci, "Cannot set link state.\n");
+ /* Port must be enabled */
+ if (!(temp & PORT_PE)) {
+ retval = -ENODEV;
+ break;
+ }
+ /* Can't set port link state above '3' (U3) */
+ if (link_state > USB_SS_PORT_LS_U3) {
+ xhci_warn(xhci, "Cannot set port %d link state %d\n",
+ wIndex, link_state);
goto error;
}
-
if (link_state == USB_SS_PORT_LS_U3) {
slot_id = xhci_find_slot_id_by_port(hcd, xhci,
wIndex + 1);