Merged in corvusvcorax/librepilot/LP-602_workaround (pull request #518)

LP-602 fix crashes, reboots and other problems with USB reconnects/replugs

Approved-by: Eric Price <corvuscorax@cybertrench.com>
Approved-by: Alessio Morale <alessiomorale@gmail.com>
Approved-by: Lalanne Laurent <f5soh@free.fr>

Author: CorvusCorax

flight/pios/stm32f4xx/libraries/STM32_USB_OTG_Driver/src/usb_dcd_int.c

@@ -681,7 +681,7 @@ static uint32_t DCD_WriteEmptyTxFifo(USB_OTG_CORE_HANDLE *pdev, uint32_t epnum)
   }
   // --- start fix
     uint32_t fifoemptymsk;
-    if (len < ep->maxpacket)
+    if (len < ep->maxpacket || ep->xfer_count==0)
     {
       // FIFO empty
       fifoemptymsk = 0x1 << epnum;

flight/pios/stm32f4xx/pios_usb.c

@@ -38,7 +38,7 @@
 #include <pios_helpers.h>
 
 /* Rx/Tx status */
-static uint8_t transfer_possible = 0;
+static volatile uint8_t transfer_possible = 0;
 
 #ifdef PIOS_INCLUDE_FREERTOS
 static void(*disconnection_cb_list[3]) (void);
@@ -148,6 +148,9 @@ int32_t PIOS_USB_Init(uint32_t *usb_id, const struct pios_usb_cfg *cfg)
  */
 int32_t PIOS_USB_ChangeConnectionState(bool connected)
 {
+#ifdef PIOS_INCLUDE_FREERTOS
+    static volatile uint8_t lastStatus = 2; // 2 is "no last status"
+#endif
     // In all cases: re-initialise USB HID driver
     if (connected) {
         transfer_possible = 1;
@@ -168,6 +171,12 @@ int32_t PIOS_USB_ChangeConnectionState(bool connected)
 
 #ifdef PIOS_INCLUDE_FREERTOS
     raiseConnectionStateCallback(connected);
+    if (lastStatus != transfer_possible) {
+        if (lastStatus == 1) {
+            raiseDisconnectionCallbacks();
+        }
+        lastStatus = transfer_possible;
+    }
 #endif
 
     return 0;
@@ -187,28 +196,19 @@ bool PIOS_USB_CheckAvailable(__attribute__((unused)) uint32_t id)
         return false;
     }
 
-    usb_found = ((usb_dev->cfg->vsense.gpio->IDR & usb_dev->cfg->vsense.init.GPIO_Pin) != 0) ^ usb_dev->cfg->vsense_active_low;
-// Please note that checks of transfer_possible and the reconnection handling is
-// suppressed for non freertos mode (aka bootloader) as this is causing problems detecting connection and
-// broken communications.
-#ifdef PIOS_INCLUDE_FREERTOS
-    static bool lastStatus = false;
-    bool status    = usb_found != 0 && transfer_possible ? 1 : 0;
-    bool reconnect = false;
-    if (xSemaphoreTakeFromISR(usb_dev->statusCheckSemaphore, NULL) == pdTRUE) {
-        reconnect  = (lastStatus && !status);
-        lastStatus = status;
-        xSemaphoreGiveFromISR(usb_dev->statusCheckSemaphore, NULL);
-    }
-    if (reconnect) {
-        raiseDisconnectionCallbacks();
-    }
-    return status;
+    return transfer_possible;
+}
 
-#else
-    return usb_found;
+/**
+ * This function returns wether a USB cable (5V pin) has been detected
+ * \return true: cable connected
+ * \return false: cable not detected (no cable or cable with no power)
+ */
+bool PIOS_USB_CableConnected(__attribute__((unused)) uint8_t id)
+{
+    struct pios_usb_dev *usb_dev = (struct pios_usb_dev *)pios_usb_id;
 
-#endif
+    return ((usb_dev->cfg->vsense.gpio->IDR & usb_dev->cfg->vsense.init.GPIO_Pin) != 0) ^ usb_dev->cfg->vsense_active_low;
 }
 
 /*

flight/pios/stm32f4xx/pios_usb_cdc.c

@@ -191,7 +191,7 @@ int32_t PIOS_USB_CDC_Init(uint32_t *usbcdc_id, const struct pios_usb_cdc_cfg *cf
 
     pios_usb_cdc_id  = (uint32_t)usb_cdc_dev;
 
-    /* Tx is not active yet */
+    /* Tx and Rx are not active yet */
     usb_cdc_dev->tx_active           = false;
 
     /* Clear stats */
@@ -607,6 +607,11 @@ static void PIOS_USB_CDC_DATA_IF_Init(uint32_t usb_cdc_id)
                                        PIOS_USB_CDC_DATA_EP_OUT_Callback,
                                        (uint32_t)usb_cdc_dev);
     usb_cdc_dev->usb_data_if_enabled = true;
+    usb_cdc_dev->tx_active = false;
+    /* Activate rx prophylactically */
+    PIOS_USBHOOK_EndpointRx(usb_cdc_dev->cfg->data_rx_ep,
+                            usb_cdc_dev->rx_packet_buffer,
+                            sizeof(usb_cdc_dev->rx_packet_buffer));
 }
 
 static void PIOS_USB_CDC_DATA_IF_DeInit(uint32_t usb_cdc_id)

flight/pios/stm32f4xx/pios_usbhook.c

@@ -280,7 +280,9 @@ static USBD_DEVICE device_callbacks = {
 static void PIOS_USBHOOK_USR_Init(void)
 {
     PIOS_USB_ChangeConnectionState(false);
-    reconnect();
+    // reconnect dev logically on init (previously a call to reconnect())
+    DCD_DevDisconnect(&pios_usb_otg_core_handle);
+    DCD_DevConnect(&pios_usb_otg_core_handle);
 }
 
 static void PIOS_USBHOOK_USR_DeviceReset(__attribute__((unused)) uint8_t speed)
@@ -491,9 +493,24 @@ static USBD_Class_cb_TypeDef class_callbacks = {
 
 static void reconnect(void)
 {
-    /* Force a physical disconnect/reconnect */
-    DCD_DevDisconnect(&pios_usb_otg_core_handle);
-    DCD_DevConnect(&pios_usb_otg_core_handle);
+    static volatile bool in_reconnect = false;
+
+    /* Force a complete device reset. This can trigger a call to reconnect() so prevent recursion */
+    if (!in_reconnect) {
+        in_reconnect = true; // save since volatile and STM32F4 is single core
+        // disable USB device
+        DCD_DevDisconnect(&pios_usb_otg_core_handle);
+        USBD_DeInit(&pios_usb_otg_core_handle);
+        USB_OTG_StopDevice(&pios_usb_otg_core_handle);
+        // enable USB device
+        USBD_Init(&pios_usb_otg_core_handle,
+                  USB_OTG_FS_CORE_ID,
+                  &device_callbacks,
+                  &class_callbacks,
+                  &user_callbacks);
+
+        in_reconnect = false;
+    }
 }
 
 #endif /* PIOS_INCLUDE_USB */

flight/targets/boards/discoveryf4bare/bootloader/main.c

@@ -82,7 +82,7 @@ int main()
     // is 2.7 volts
     check_bor();
 
-    USB_connected = PIOS_USB_CheckAvailable(0);
+    USB_connected = PIOS_USB_CableConnected(0);
 
     if (PIOS_IAP_CheckRequest() == true) {
         PIOS_DELAY_WaitmS(1000);

flight/targets/boards/osd/bootloader/main.c

@@ -76,7 +76,7 @@ int main()
     PIOS_Board_Init();
     PIOS_IAP_Init();
 
-    USB_connected = PIOS_USB_CheckAvailable(0);
+    USB_connected = PIOS_USB_CableConnected(0);
 
     if (PIOS_IAP_CheckRequest() == true) {
         PIOS_DELAY_WaitmS(1000);

flight/targets/boards/revolution/bootloader/main.c

@@ -82,7 +82,7 @@ int main()
     // is 2.7 volts
     check_bor();
 
-    USB_connected = PIOS_USB_CheckAvailable(0);
+    USB_connected = PIOS_USB_CableConnected(0);
 
     if (PIOS_IAP_CheckRequest() == true) {
         PIOS_DELAY_WaitmS(1000);

flight/targets/boards/revonano/bootloader/main.c

@@ -82,7 +82,7 @@ int main()
     // is 2.7 volts
     check_bor();
 
-    USB_connected = PIOS_USB_CheckAvailable(0);
+    USB_connected = PIOS_USB_CableConnected(0);
 
     if (PIOS_IAP_CheckRequest() == true) {
         PIOS_DELAY_WaitmS(1000);

flight/targets/boards/revoproto/bootloader/main.c

@@ -82,7 +82,7 @@ int main()
     // is 2.7 volts
     check_bor();
 
-    USB_connected = PIOS_USB_CheckAvailable(0);
+    USB_connected = PIOS_USB_CableConnected(0);
 
     if (PIOS_IAP_CheckRequest() == true) {
         PIOS_DELAY_WaitmS(1000);

flight/targets/boards/sparky2/bootloader/main.c

@@ -83,7 +83,7 @@ int main()
     // is 2.7 volts
     check_bor();
 
-    USB_connected = PIOS_USB_CheckAvailable(0);
+    USB_connected = PIOS_USB_CableConnected(0);
 
     if (PIOS_IAP_CheckRequest() == true) {
         PIOS_DELAY_WaitmS(1000);