usb: typec: ucsi: Ack unsupported commands

If a command completes the OPM must send an ack. This applies
to unsupported commands, too.

Send the required ACK for unsupported commands.
Signed-off-by: Christian A. Ehrhardt <lk@c--e.de>
Cc: stable <stable@kernel.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8550-QRD
Link: https://lore.kernel.org/r/20240320073927.1641788-4-lk@c--e.deSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/typec/ucsi/ucsi.c

@@ -151,8 +151,12 @@ static int ucsi_exec_command(struct ucsi *ucsi, u64 cmd)
 	if (!(cci & UCSI_CCI_COMMAND_COMPLETE))
 		return -EIO;
 
-	if (cci & UCSI_CCI_NOT_SUPPORTED)
+	if (cci & UCSI_CCI_NOT_SUPPORTED) {
+		if (ucsi_acknowledge_command(ucsi) < 0)
+			dev_err(ucsi->dev,
+				"ACK of unsupported command failed\n");
 		return -EOPNOTSUPP;
+	}
 
 	if (cci & UCSI_CCI_ERROR) {
 		if (cmd == UCSI_GET_ERROR_STATUS)