atmodem: Add funny ZTE quirk for GPRS context support

diff --git a/drivers/atmodem/gprs-context.c b/drivers/atmodem/gprs-context.c
index c5dabf2..cf80d5b 100644 (file)
--- a/drivers/atmodem/gprs-context.c
+++ b/drivers/atmodem/gprs-context.c
@@ -241,6 +241,27 @@ static void at_gprs_activate_primary(struct ofono_gprs_context *gc,
 
        gcd->state = STATE_ENABLING;
 
+       if (gcd->vendor == OFONO_VENDOR_ZTE) {
+               GAtChat *chat = g_at_chat_get_slave(gcd->chat);
+
+               /*
+                * The modem port of ZTE devices with certain firmware
+                * versions ends up getting suspended. It will no longer
+                * signal POLLOUT and becomes pretty unresponsive.
+                *
+                * To wake up the modem port, the only reliable method
+                * found so far is AT+ZOPRT power mode command. It is
+                * enough to ask for the current mode and the modem
+                * port wakes up and accepts commands again.
+                *
+                * And since the modem port is suspended, this command
+                * needs to be send on the control port of course.
+                *
+                */
+               g_at_chat_send(chat, "AT+ZOPRT?", none_prefix,
+                                               NULL, NULL, NULL);
+       }
+
        len = snprintf(buf, sizeof(buf), "AT+CGDCONT=%u,\"IP\"", ctx->cid);
 
        if (ctx->apn)