[PATCH] huawei: retry connect/disconnect attempt upon NDISSTATQRY failures

[Prathmesh Prabhu]

This is a workaround for a bug in the modem firmware that causes the NDISSTATQRY
response to be an error response intermittently. With this patch, the connect /
disconnect attempt ignores a few of these error responses. Note that the overall
time-out for the connect/disconnect is not affected by this change.
---
 plugins/huawei/mm-broadband-bearer-huawei.c | 54 ++++++++++++++++++-----------
 1 file changed, 34 insertions(+), 20 deletions(-)

diff --git a/plugins/huawei/mm-broadband-bearer-huawei.c b/plugins/huawei/mm-broadband-bearer-huawei.c
index 2e1b0b0..75d3566 100644
--- a/plugins/huawei/mm-broadband-bearer-huawei.c
+++ b/plugins/huawei/mm-broadband-bearer-huawei.c
@@ -57,6 +57,7 @@ typedef struct {
     GSimpleAsyncResult *result;
     Connect3gppContextStep step;
     guint check_count;
+    guint failed_ndisstatqry_count;
 } Connect3gppContext;
 
 static void
@@ -130,20 +131,15 @@ connect_ndisstatqry_check_ready (MMBaseModem *modem,
                                                &ipv6_available,
                                                &ipv6_connected,
                                                &error)) {
-        mm_dbg ("Modem doesn't properly support ^NDISSTATQRY command: %s", error->message);
+        ctx->failed_ndisstatqry_count++;
+        mm_dbg ("Unexpected response to ^NDISSTATQRY command: %s (Attempts so far: %d)",
+                error->message, ctx->failed_ndisstatqry_count);
         g_error_free (error);
-
-        ctx->self->priv->connect_pending = NULL;
-        g_simple_async_result_set_error (ctx->result,
-                                         MM_MOBILE_EQUIPMENT_ERROR,
-                                         MM_MOBILE_EQUIPMENT_ERROR_NOT_SUPPORTED,
-                                         "Connection attempt not supported");
-        connect_3gpp_context_complete_and_free (ctx);
-        return;
+        response = NULL;  /* Set to NULL to skip steps below. */
     }
 
     /* Connected in IPv4? */
-    if (ipv4_available && ipv4_connected) {
+    if (response && ipv4_available && ipv4_connected) {
         /* Success! */
         ctx->step++;
         connect_3gpp_context_step (ctx);
@@ -315,6 +311,17 @@ connect_3gpp_context_step (Connect3gppContext *ctx)
             connect_3gpp_context_complete_and_free (ctx);
             return;
         }
+        /* Give up if too many unexpected responses to NIDSSTATQRY are encountered. */
+        if (ctx->failed_ndisstatqry_count > 3) {
+            /* Clear context */
+            ctx->self->priv->connect_pending = NULL;
+            g_simple_async_result_set_error (ctx->result,
+                                             MM_MOBILE_EQUIPMENT_ERROR,
+                                             MM_MOBILE_EQUIPMENT_ERROR_NOT_SUPPORTED,
+                                             "Connection attempt not supported.");
+            connect_3gpp_context_complete_and_free (ctx);
+            return;
+        }
 
         /* Check if connected */
         ctx->check_count++;
@@ -413,6 +420,7 @@ typedef struct {
     GSimpleAsyncResult *result;
     Disconnect3gppContextStep step;
     guint check_count;
+    guint failed_ndisstatqry_count;
 } Disconnect3gppContext;
 
 static void
@@ -480,20 +488,15 @@ disconnect_ndisstatqry_check_ready (MMBaseModem *modem,
                                                &ipv6_available,
                                                &ipv6_connected,
                                                &error)) {
-        mm_dbg ("Modem doesn't properly support ^NDISSTATQRY command: %s", error->message);
+        ctx->failed_ndisstatqry_count++;
+        mm_dbg ("Unexpected response to ^NDISSTATQRY command: %s (Attempts so far: %d)",
+                error->message, ctx->failed_ndisstatqry_count);
         g_error_free (error);
-
-        ctx->self->priv->disconnect_pending = NULL;
-        g_simple_async_result_set_error (ctx->result,
-                                         MM_MOBILE_EQUIPMENT_ERROR,
-                                         MM_MOBILE_EQUIPMENT_ERROR_NOT_SUPPORTED,
-                                         "Disconnection attempt not supported");
-        disconnect_3gpp_context_complete_and_free (ctx);
-        return;
+        response = NULL;  /* Set to NULL to skip steps below. */
     }
 
     /* Disconnected IPv4? */
-    if (ipv4_available && !ipv4_connected) {
+    if (response && ipv4_available && !ipv4_connected) {
         /* Success! */
         ctx->step++;
         disconnect_3gpp_context_step (ctx);
@@ -568,6 +571,17 @@ disconnect_3gpp_context_step (Disconnect3gppContext *ctx)
             disconnect_3gpp_context_complete_and_free (ctx);
             return;
         }
+        /* Give up if too many unexpected responses to NIDSSTATQRY are encountered. */
+        if (ctx->failed_ndisstatqry_count > 3) {
+            /* Clear context */
+            ctx->self->priv->disconnect_pending = NULL;
+            g_simple_async_result_set_error (ctx->result,
+                                             MM_MOBILE_EQUIPMENT_ERROR,
+                                             MM_MOBILE_EQUIPMENT_ERROR_NOT_SUPPORTED,
+                                             "Disconnection attempt not supported.");
+            disconnect_3gpp_context_complete_and_free (ctx);
+            return;
+        }
 
         /* Check if disconnected */
         ctx->check_count++;
-- 
1.8.3.1