}
/**
+ * gsm_read_ea_val - read a value until EA
+ * @val: variable holding value
+ * @data: buffer of data
+ * @dlen: length of data
+ *
+ * Processes an EA value. Updates the passed variable and
+ * returns the processed data length.
+ */
+static unsigned int gsm_read_ea_val(unsigned int *val, const u8 *data, int dlen)
+{
+ unsigned int len = 0;
+
+ for (; dlen > 0; dlen--) {
+ len++;
+ if (gsm_read_ea(val, *data++))
+ break;
+ }
+ return len;
+}
+
+/**
* gsm_encode_modem - encode modem data bits
* @dlci: DLCI to encode from
*
}
/**
+ * gsm_is_flow_ctrl_msg - checks if flow control message
+ * @msg: message to check
+ *
+ * Returns true if the given message is a flow control command of the
+ * control channel. False is returned in any other case.
+ */
+static bool gsm_is_flow_ctrl_msg(struct gsm_msg *msg)
+{
+ unsigned int cmd;
+
+ if (msg->addr > 0)
+ return false;
+
+ switch (msg->ctrl & ~PF) {
+ case UI:
+ case UIH:
+ cmd = 0;
+ if (gsm_read_ea_val(&cmd, msg->data + 2, msg->len - 2) < 1)
+ break;
+ switch (cmd & ~PF) {
+ case CMD_FCOFF:
+ case CMD_FCON:
+ return true;
+ }
+ break;
+ }
+
+ return false;
+}
+
+/**
* gsm_data_kick - poke the queue
* @gsm: GSM Mux
* @dlci: DLCI sending the data
int len;
list_for_each_entry_safe(msg, nmsg, &gsm->tx_list, list) {
- if (gsm->constipated && msg->addr)
+ if (gsm->constipated && !gsm_is_flow_ctrl_msg(msg))
continue;
if (gsm->encoding != 0) {
gsm->txframe[0] = GSM1_SOF;