device: don't reprobe if device is gone

When a QMI/MBIM device is unplugged, we first get the notification
from the proxy that the communication is broken, and then we get the
kernel event reporting that the cdc-wdm port is gone.

If we reprobe the device as soon as the proxy notifies us that the
communication is broken, we would end up trying to reprobe the cdc-wdm
port when it's already gone, and we end up trying to create a modem
object when we shouldn't:

   <debug> [1577963152.429386] (ttyUSB0) unexpected port hangup!
   <debug> [1577963152.429506] (ttyUSB0) forced to close port
   <debug> [1577963152.429546] (ttyUSB0) device open count is 0 (close)
   <debug> [1577963152.429582] (ttyUSB0) closing serial port...
   <debug> [1577963152.429653] (ttyUSB0) serial port closed
   <debug> [1577963152.430340] (ttyUSB2) unexpected port hangup!
   <debug> [1577963152.430391] (ttyUSB2) forced to close port
   <debug> [1577963152.430418] (ttyUSB2) device open count is 0 (close)
   <debug> [1577963152.430451] (ttyUSB2) closing serial port...
   <debug> [1577963152.430517] (ttyUSB2) serial port closed
   <info>  [1577963152.436932] (tty/ttyUSB0): released by device '/sys/devices/pci0000:00/0000:00:14.0/usb2/2-3'
   <info>  [1577963152.439176] (tty/ttyUSB1): released by device '/sys/devices/pci0000:00/0000:00:14.0/usb2/2-3'
   <info>  [1577963152.440409] (tty/ttyUSB2): released by device '/sys/devices/pci0000:00/0000:00:14.0/usb2/2-3'
   <info>  [1577963152.447977] (net/wwan1): released by device '/sys/devices/pci0000:00/0000:00:14.0/usb2/2-3'
   Cannot read from istream: connection broken
   <info>  [1577963152.458878] Connection to qmi-proxy for /dev/cdc-wdm1 lost, reprobing
   <debug> [1577963152.459144] [device /sys/devices/pci0000:00/0000:00:14.0/usb2/2-3] unexported modem from path '/org/freedesktop/ModemManager1/Modem/1'
   <debug> [1577963152.460151] (ttyUSB1) forced to close port
   <info>  [1577963152.460182] [device /sys/devices/pci0000:00/0000:00:14.0/usb2/2-3] creating modem with plugin 'Sierra' and '1' ports
   <debug> [1577963152.460199] QMI-powered Sierra modem found...
   <debug> [1577963152.460382] (cdc-wdm1) type 'qmi' claimed by /sys/devices/pci0000:00/0000:00:14.0/usb2/2-3
   <debug> [1577963152.460417] Modem (Sierra) '/sys/devices/pci0000:00/0000:00:14.0/usb2/2-3' completely disposed
   <warn>  [1577963152.460431] Could not recreate modem for device '/sys/devices/pci0000:00/0000:00:14.0/usb2/2-3': Failed to find a net port in the QMI modem
   <debug> [1577963152.460526] Modem (Sierra) '/sys/devices/pci0000:00/0000:00:14.0/usb2/2-3' completely disposed
   <info>  [1577963152.460627] (usbmisc/cdc-wdm1): released by device '/sys/devices/pci0000:00/0000:00:14.0/usb2/2-3'
   <debug> [1577963152.460666] Removing empty device '/sys/devices/pci0000:00/0000:00:14.0/usb2/2-3'

Fix this by delaying the reprobing attempt some time, and make sure we
cancel the reprobing if the device detects that all ports are gone.

1 files changed, 27 insertions, 13 deletions

diff --git a/src/mm-device.c b/src/mm-device.c
index 55c51186..86baf7c7 100644
--- a/src/mm-device.c
+++ b/src/mm-device.c
@@ -86,6 +86,9 @@ struct _MMDevicePrivate {
 
     /* Virtual ports */
     gchar **virtual_ports;
+
+    /* Scheduled reprobe */
+    guint reprobe_id;
 };
 
 /*****************************************************************************/
@@ -327,6 +330,24 @@ mm_device_remove_modem (MMDevice  *self)
 
 /*****************************************************************************/
 
+#define REPROBE_SECS 2
+
+static gboolean
+reprobe (MMDevice *self)
+{
+    GError *error = NULL;
+
+    if (!mm_device_create_modem (self, &error)) {
+        mm_warn ("Could not recreate modem for device '%s': %s",
+                 self->priv->uid,
+                 error ? error->message : "unknown");
+        g_error_free (error);
+    } else
+        mm_dbg ("Modem recreated for device '%s'", self->priv->uid);
+
+    return G_SOURCE_REMOVE;
+}
+
 static void
 modem_valid (MMBaseModem *modem,
              GParamSpec  *pspec,
@@ -335,19 +356,8 @@ modem_valid (MMBaseModem *modem,
     if (!mm_base_modem_get_valid (modem)) {
         /* Modem no longer valid */
         mm_device_remove_modem (self);
-
-        if (mm_base_modem_get_reprobe (modem)) {
-            GError *error = NULL;
-
-            if (!mm_device_create_modem (self, &error)) {
-                mm_warn ("Could not recreate modem for device '%s': %s",
-                         self->priv->uid,
-                         error ? error->message : "unknown");
-                g_error_free (error);
-            } else {
-                mm_dbg ("Modem recreated for device '%s'", self->priv->uid);
-            }
-        }
+        if (mm_base_modem_get_reprobe (modem))
+            self->priv->reprobe_id = g_timeout_add_seconds (REPROBE_SECS, (GSourceFunc)reprobe, self);
     } else {
         /* Modem now valid, export it, but only if we really have it around.
          * It may happen that the initialization sequence fails because the
@@ -734,6 +744,10 @@ dispose (GObject *object)
 {
     MMDevice *self = MM_DEVICE (object);
 
+    if (self->priv->reprobe_id) {
+        g_source_remove (self->priv->reprobe_id);
+        self->priv->reprobe_id = 0;
+    }
     g_clear_object (&(self->priv->object_manager));
     g_clear_object (&(self->priv->plugin));
     g_list_free_full (self->priv->port_probes, g_object_unref);