Protection against concurrent access to USBHost

Fixed regression: Protection against concurrent access to USBHost using
locking class
Use Lock class within USBHost

libraries/USBHost/USBHost/USBHost.cpp

@@ -79,7 +79,9 @@ void USBHost::usb_process() {
                     too_many_hub = false;
                     buf[4] = 0;
                 
-                    usb_mutex.lock();
+                    do
+                    {
+                      Lock lock(this);
                     
                       for (i = 0; i < MAX_DEVICE_CONNECTED; i++) {
                           if (!deviceInUse[i]) {
@@ -93,7 +95,6 @@ void USBHost::usb_process() {
                       
                       if (i == MAX_DEVICE_CONNECTED) {
                           USB_ERR("Too many device connected!!\r\n");
-                        usb_mutex.unlock();
                           continue;
                       }
                       
@@ -183,14 +184,16 @@ void USBHost::usb_process() {
                           deviceInUse[i] = true;
                       }
                       
-                    usb_mutex.unlock();
+                    } while(0);
                     
                     break;
                     
                 // a device has been disconnected
                 case DEVICE_DISCONNECTED_EVENT:
                     
-                    usb_mutex.lock();
+                    do
+                    {
+                      Lock lock(this);
                 
                       controlListState = disableList(CONTROL_ENDPOINT);
                       bulkListState = disableList(BULK_ENDPOINT);
@@ -205,7 +208,7 @@ void USBHost::usb_process() {
                       if (bulkListState) enableList(BULK_ENDPOINT);
                       if (interruptListState) enableList(INTERRUPT_ENDPOINT);
                     
-                    usb_mutex.unlock();
+                    } while(0);
                     
                     break;
                     
@@ -278,6 +281,15 @@ USBHost::USBHost() : usbThread(USBHost::usb_process_static, (void *)this, osPrio
 #endif
 }
 
+USBHost::Lock::Lock(USBHost* pHost) : m_pHost(pHost)
+{
+  m_pHost->usb_mutex.lock();
+}
+
+USBHost::Lock::~Lock()
+{
+  m_pHost->usb_mutex.unlock();
+}
 
 void USBHost::transferCompleted(volatile uint32_t addr)
 {
@@ -810,13 +822,14 @@ USB_TYPE USBHost::enumerate(USBDeviceConnected * dev, IUSBEnumerator* pEnumerato
     uint16_t total_conf_descr_length = 0;
     USB_TYPE res;
     
-    usb_mutex.lock();
+    do
+    {
+      Lock lock(this);
       
       // don't enumerate a device which all interfaces are registered to a specific driver
       int index = findDevice(dev);
       
       if (index == -1) {
-        usb_mutex.unlock();
           return USB_TYPE_ERROR;
       }
       
@@ -825,7 +838,6 @@ USB_TYPE USBHost::enumerate(USBDeviceConnected * dev, IUSBEnumerator* pEnumerato
       USB_DBG("dev: %p nb_intf_attached: %d", dev, nb_intf_attached);
       if ((nb_intf_attached != 0) && (dev->getNbIntf() == nb_intf_attached)) {
           USB_DBG("Don't enumerate dev: %p because all intf are registered with a driver", dev);
-        usb_mutex.unlock();
           return USB_TYPE_OK;
       }
       
@@ -836,7 +848,6 @@ USB_TYPE USBHost::enumerate(USBDeviceConnected * dev, IUSBEnumerator* pEnumerato
 
       if (res != USB_TYPE_OK) {
           USB_DBG("GET DEV DESCR FAILED");
-        usb_mutex.unlock();
           return res;
       }
       
@@ -851,7 +862,6 @@ USB_TYPE USBHost::enumerate(USBDeviceConnected * dev, IUSBEnumerator* pEnumerato
 
       res = getConfigurationDescriptor(dev, data, sizeof(data), &total_conf_descr_length);
       if (res != USB_TYPE_OK) {
-        usb_mutex.unlock();
           return res;
       }
 
@@ -874,7 +884,6 @@ USB_TYPE USBHost::enumerate(USBDeviceConnected * dev, IUSBEnumerator* pEnumerato
 
           if (res != USB_TYPE_OK) {
               USB_DBG("SET CONF FAILED");
-            usb_mutex.unlock();
               return res;
           }
       }
@@ -883,10 +892,11 @@ USB_TYPE USBHost::enumerate(USBDeviceConnected * dev, IUSBEnumerator* pEnumerato
 
       // Now the device is enumerated!
       USB_DBG("dev %p is enumerated\r\n", dev);
-    usb_mutex.unlock();
+      
+    } while(0);
 
     // Some devices may require this delay
-    wait_ms(100);
+    Thread::wait(100);
 
     return USB_TYPE_OK;
 }
@@ -987,38 +997,33 @@ USB_TYPE USBHost::generalTransfer(USBDeviceConnected * dev, USBEndpoint * ep, ui
     USB_DBG_TRANSFER("----- %s %s [dev: %p - %s - hub: %d - port: %d - addr: %d - ep: %02X]------", type_str, (write) ? "WRITE" : "READ", dev, dev->getName(ep->getIntfNb()), dev->getHub(), dev->getPort(), dev->getAddress(), ep->getAddress());
 #endif
     
-    usb_mutex.lock();
+    Lock lock(this);
     
     USB_TYPE res;
     ENDPOINT_DIRECTION dir = (write) ? OUT : IN;
     
     if (dev == NULL) {
         USB_ERR("dev NULL");
-        usb_mutex.unlock();
         return USB_TYPE_ERROR;
     }
 
     if (ep == NULL) {
         USB_ERR("ep NULL");
-        usb_mutex.unlock();
         return USB_TYPE_ERROR;
     }
 
     if (ep->getState() != USB_TYPE_IDLE) {
         USB_WARN("[ep: %p - dev: %p - %s] NOT IDLE: %s", ep, ep->dev, ep->dev->getName(ep->getIntfNb()), ep->getStateString());
-        usb_mutex.unlock();
         return ep->getState();
     }
 
     if ((ep->getDir() != dir) || (ep->getType() != type)) {
         USB_ERR("[ep: %p - dev: %p] wrong dir or bad USBEndpoint type", ep, ep->dev);
-        usb_mutex.unlock();
         return USB_TYPE_ERROR;
     }
 
     if (dev->getAddress() != ep->getDeviceAddress()) {
         USB_ERR("[ep: %p - dev: %p] USBEndpoint addr and device addr don't match", ep, ep->dev);
-        usb_mutex.unlock();
         return USB_TYPE_ERROR;
     }
     
@@ -1040,15 +1045,12 @@ USB_TYPE USBHost::generalTransfer(USBDeviceConnected * dev, USBEndpoint * ep, ui
         USB_DBG_TRANSFER("%s TRANSFER res: %s on ep: %p\r\n", type_str, ep->getStateString(), ep);
         
         if (res != USB_TYPE_IDLE) {
-            usb_mutex.unlock();
             return res;
         }
         
-        usb_mutex.unlock();
         return USB_TYPE_OK;
     }
     
-    usb_mutex.unlock();
     return USB_TYPE_PROCESSING;
 
 }
@@ -1064,7 +1066,7 @@ USB_TYPE USBHost::controlWrite(USBDeviceConnected * dev, uint8_t requestType, ui
 
 USB_TYPE USBHost::controlTransfer(USBDeviceConnected * dev, uint8_t requestType, uint8_t request, uint32_t value, uint32_t index, uint8_t * buf, uint32_t len, bool write)
 {
-    usb_mutex.lock();
+    Lock lock(this);
     USB_DBG_TRANSFER("----- CONTROL %s [dev: %p - hub: %d - port: %d] ------", (write) ? "WRITE" : "READ", dev, dev->getHub(), dev->getPort());
 
     int length_transfer = len;
@@ -1098,7 +1100,6 @@ USB_TYPE USBHost::controlTransfer(USBDeviceConnected * dev, uint8_t requestType,
     USB_DBG_TRANSFER("CONTROL setup stage %s", control->getStateString());
 
     if (res != USB_TYPE_IDLE) {
-        usb_mutex.unlock();
         return res;
     }
 
@@ -1126,7 +1127,6 @@ USB_TYPE USBHost::controlTransfer(USBDeviceConnected * dev, uint8_t requestType,
 #endif
 
         if (res != USB_TYPE_IDLE) {
-            usb_mutex.unlock();
             return res;
         }
     }
@@ -1139,7 +1139,6 @@ USB_TYPE USBHost::controlTransfer(USBDeviceConnected * dev, uint8_t requestType,
     res = control->getState();
 
     USB_DBG_TRANSFER("CONTROL ack stage %s", control->getStateString());
-    usb_mutex.unlock();
 
     if (res != USB_TYPE_IDLE)
         return res;

libraries/USBHost/USBHost/USBHost.h

@@ -187,6 +187,18 @@ public:
         }
     }
     
+    /**
+     * Instantiate to protect USB thread from accessing shared objects (USBConnectedDevices and Interfaces)
+     */
+    class Lock
+    {
+    public:
+      Lock(USBHost* pHost);  
+      ~Lock();  
+    private:
+      USBHost* m_pHost;
+    };
+    
     friend class USBHostHub;
 
 protected:

libraries/USBHost/USBHost3GModule/WANDongle.cpp

@@ -20,11 +20,6 @@
 
 #ifdef USBHOST_3GMODULE
 
-#define __DEBUG__ 0
-#ifndef __MODULE__
-#define __MODULE__ "WANDongle.cpp"
-#endif
-
 #include "dbg.h"
 #include <stdint.h>
 #include "rtos.h"
@@ -50,11 +45,15 @@ bool WANDongle::tryConnect()
   USB_DBG("Trying to connect device");
 
   if (dev_connected) {
+      USB_DBG("Device is already connected!");    
       return true;
   }
   
   m_pInitializer = NULL;
   
+  //Protect from concurrent access from USB thread
+  USBHost::Lock lock(host);
+
   for (int i = 0; i < MAX_DEVICE_CONNECTED; i++)
   {
       if ((dev = host->getDevice(i)) != NULL)