telit: add initial delay for AT ports to become responsive

Add a polling mechanism for port responsiveness, since some modem
families require some time before being usable after the serial
ports have been exposed by the kernel.

1 files changed, 81 insertions, 1 deletions

diff --git a/plugins/telit/mm-common-telit.c b/plugins/telit/mm-common-telit.c
index 0493fd54..f53f5b75 100644
--- a/plugins/telit/mm-common-telit.c
+++ b/plugins/telit/mm-common-telit.c
@@ -17,6 +17,7 @@
 
 #include "mm-common-telit.h"
 #include "mm-log-object.h"
+#include "mm-serial-parsers.h"
 
 /*****************************************************************************/
 
@@ -28,6 +29,11 @@
 
 #define TELIT_GE910_FAMILY_PID     0x0022
 
+/* The following number of retries of the port responsiveness
+ * check allows having up to 30 seconds of wait, that should
+ * be fine for most of the modems */
+#define TELIT_PORT_CHECK_RETRIES   6
+
 gboolean
 telit_grab_port (MMPlugin *self,
                  MMBaseModem *modem,
@@ -88,6 +94,7 @@ typedef struct {
     MMPortSerialAt *port;
     gboolean getportcfg_done;
     guint getportcfg_retries;
+    guint port_responsive_retries;
 } TelitCustomInitContext;
 
 gboolean
@@ -274,6 +281,67 @@ out:
     g_object_unref (task);
 }
 
+static void at_ready (MMPortSerialAt *port,
+                      GAsyncResult   *res,
+                      GTask          *task);
+
+static void
+wait_for_ready (GTask *task)
+{
+    TelitCustomInitContext *ctx;
+
+    ctx = g_task_get_task_data (task);
+
+    if (ctx->port_responsive_retries == 0) {
+        telit_custom_init_step (task);
+        return;
+    }
+    ctx->port_responsive_retries--;
+
+    mm_port_serial_at_command (
+        ctx->port,
+        "AT",
+        5,
+        FALSE, /* raw */
+        FALSE, /* allow_cached */
+        g_task_get_cancellable (task),
+        (GAsyncReadyCallback)at_ready,
+        task);
+}
+
+static void
+at_ready (MMPortSerialAt *port,
+          GAsyncResult   *res,
+          GTask          *task)
+{
+    MMPortProbe       *probe;
+    g_autoptr(GError)  error = NULL;
+
+    probe = g_task_get_source_object (task);
+
+    mm_port_serial_at_command_finish (port, res, &error);
+    if (error) {
+        /* On a timeout or send error, wait */
+        if (g_error_matches (error, MM_SERIAL_ERROR, MM_SERIAL_ERROR_RESPONSE_TIMEOUT) ||
+            g_error_matches (error, MM_SERIAL_ERROR, MM_SERIAL_ERROR_SEND_FAILED)) {
+            wait_for_ready (task);
+            return;
+        }
+        /* On an unknown error, make it fatal */
+        if (!mm_serial_parser_v1_is_known_error (error)) {
+            mm_obj_warn (probe, "custom port initialization logic failed: %s", error->message);
+            g_task_return_boolean (task, TRUE);
+            g_object_unref (task);
+            return;
+        }
+    }
+
+    /* When successful mark the port as AT and continue checking #PORTCFG */
+    mm_obj_dbg (probe, "port is AT");
+    mm_port_probe_set_result_at (probe, TRUE);
+    telit_custom_init_step (task);
+}
+
 void
 telit_custom_init (MMPortProbe *probe,
                    MMPortSerialAt *port,
@@ -283,15 +351,27 @@ telit_custom_init (MMPortProbe *probe,
 {
     TelitCustomInitContext *ctx;
     GTask *task;
+    gboolean wait_needed;
 
     ctx = g_slice_new (TelitCustomInitContext);
     ctx->port = g_object_ref (port);
     ctx->getportcfg_done = FALSE;
     ctx->getportcfg_retries = 3;
-
+    ctx->port_responsive_retries = TELIT_PORT_CHECK_RETRIES;
     task = g_task_new (probe, cancellable, callback, user_data);
     g_task_set_check_cancellable (task, FALSE);
     g_task_set_task_data (task, ctx, (GDestroyNotify)telit_custom_init_context_free);
 
+    /* Some Telit modems require an initial delay for the ports to be responsive
+     * If no explicit tag is present, the modem does not need this step
+     * and can directly look for #PORTCFG support */
+    wait_needed = mm_kernel_device_get_global_property_as_boolean (mm_port_probe_peek_port (probe),
+                                                                   "ID_MM_TELIT_PORT_DELAY");
+    if (wait_needed) {
+        mm_obj_dbg (probe, "Start polling for port responsiveness");
+        wait_for_ready (task);
+        return;
+    }
+
     telit_custom_init_step (task);
 }