[usb-moded] Use single function to exit charging fallback. Fixes JB#3…

…7759

Whether and when we can switch for example from charging fallback to
developer mode depends on multiple triggers - the order of which might vary
from one device/bootup to another. Using custom state evaluation code at
each possible trigger location easily causes unexpected results like device
staying in fallback charging mode until the cable is re-attached.

Add a state evaluation function and call it from those triggers that
potentially allow exit from the charging fallback mode.

Signed-off-by: Simo Piiroinen <simo.piiroinen@jollamobile.com>

src/usb_moded-devicelock.c

@@ -114,29 +114,18 @@ gboolean usb_moded_get_export_permission(void)
 
 static void devicelock_state_changed(devicelock_state_t state)
 {
-    if( device_lock_state != state ) {
-        log_debug("devicelock state: %s -> %s",
-                  devicelock_state_repr(device_lock_state),
-                  devicelock_state_repr(state));
-        device_lock_state = state;
-
-        if( device_lock_state == DEVICE_LOCK_UNLOCKED &&
-            get_usb_connection_state() == 1 )
-        {
-            const char *usb_mode = get_usb_mode();
-            log_debug("usb_mode %s\n", usb_mode);
-
-            /* if the mode is MODE_CHARGING_FALLBACK we know the user
-             * has not selected any mode, in case it things are still
-             * undefined it cannot hurt to try again to set a mode */
-            if(!strcmp(usb_mode, MODE_UNDEFINED) ||
-               !strcmp(usb_mode, MODE_CHARGING_FALLBACK))
-            {
-                log_debug("set_usb");
-                set_usb_connected_state();
-            }
-        }
-    }
+    if( device_lock_state == state )
+        goto EXIT;
+
+    log_debug("devicelock state: %s -> %s",
+              devicelock_state_repr(device_lock_state),
+              devicelock_state_repr(state));
+    device_lock_state = state;
+
+    rethink_usb_charging_fallback();
+
+EXIT:
+    return;
 }
 
 static DBusPendingCall *devicelock_state_query_pc = 0;

src/usb_moded-dsme.c

@@ -26,6 +26,8 @@
 #include <dbus/dbus-glib-lowlevel.h>
 
 #include "usb_moded-dsme.h"
+#include "usb_moded.h"
+
 #include "usb_moded-dbus-private.h"
 #include "usb_moded-log.h"
 
@@ -87,11 +89,16 @@ static void device_state_changed(const char *state)
 
     log_debug("device state: %s", state ?: "(null)");
 
-    if( in_user_state != to_user_state ) {
-        in_user_state = to_user_state;
-        log_debug("in user state: %s",
-                  in_user_state ? "true" : "false");
-    }
+    if( in_user_state == to_user_state )
+        goto EXIT;
+
+    in_user_state = to_user_state;
+    log_debug("in user state: %s", in_user_state ? "true" : "false");
+
+    rethink_usb_charging_fallback();
+
+EXIT:
+    return;
 }
 
 static DBusPendingCall *device_state_query_pc = 0;

src/usb_moded.c

@@ -251,6 +251,46 @@ void set_charger_connected(gboolean state)
     current_mode.connected = FALSE;
   }
 }
+/** Check if we can/should leave charging fallback mode
+ */
+void
+rethink_usb_charging_fallback(void)
+{
+    /* Cable must be connected and suitable usb-mode mode
+     * selected for any of this to apply.
+     */
+    if( !get_usb_connection_state() )
+        goto EXIT;
+
+    const char *usb_mode = get_usb_mode();
+
+    if( strcmp(usb_mode, MODE_UNDEFINED) &&
+        strcmp(usb_mode, MODE_CHARGING_FALLBACK) )
+        goto EXIT;
+
+    /* If device locking is supported, the device must be in
+     * unlocked state (or rescue mode must be active).
+     */
+#ifdef MEEGOLOCK
+    if( !usb_moded_get_export_permission() && !rescue_mode ) {
+        log_notice("device is locked; stay in %s", usb_mode);
+        goto EXIT;
+    }
+#endif
+
+    /* Device must be in USER state or in rescue mode
+     */
+    if( !is_in_user_state() && !rescue_mode ) {
+        log_notice("device is not in USER mode; stay in %s", usb_mode);
+        goto EXIT;
+    }
+
+    log_debug("attempt to leave %s", usb_mode);
+    set_usb_connected_state();
+
+EXIT:
+    return;
+}
 
 /** set the chosen usb state
  *

src/usb_moded.h

@@ -61,6 +61,7 @@ typedef struct usb_mode
 void set_usb_connected(gboolean connected);
 void set_usb_connected_state(void);
 void set_usb_mode(const char *mode);
+void rethink_usb_charging_fallback(void);
 const char * get_usb_mode(void);
 void set_usb_module(const char *module);
 const char * get_usb_module(void);