Do not use wrong serial port (flipperdevices#148)

* Do not use a device that fails to open

When the USB device fails to open the application continues to use the
device with unfilled device data with empty serial number.

Then the application attempts to find a serial port matching the
unfilled device info structure. If you happen to have a Chinese serial
port with empty serial number the application will attempt to use it.

Invalidate the device info when filling out the data fails.

Signed-off-by: Michal Suchanek <[email protected]>

* Properly report USB device error

Currently the return value from libusb functions is ignored, and only a
generic error message is printed.

Use the libusb facility for converting error codes to error messages to
provide meaningful error message to the user.

Signed-off-by: Michal Suchanek <[email protected]>

Signed-off-by: Michal Suchanek <[email protected]>

dfu/libusb/usbdevicedetector.cpp

@@ -107,56 +107,57 @@ USBDeviceInfo USBDeviceDetector::fillDeviceInfo(const USBDeviceInfo &deviceInfo)
     libusb_device_descriptor desc;
     struct libusb_device_handle *handle;
 
-    bool descOk = false, devOk = false, mfgOk = false, productOk = false, serialOk = false;
+    int descOk = -99, devOk = -99, mfgOk = -99, productOk = -99, serialOk = -99;
 
     do {
         do {
-            descOk = !libusb_get_device_descriptor(dev, &desc);
-            if(!descOk) break;
+            descOk = libusb_get_device_descriptor(dev, &desc);
+            if(descOk < 0) break;
 
-            devOk = !libusb_open(dev, &handle);
-            if(!devOk) break;
+            devOk = libusb_open(dev, &handle);
+            if(devOk < 0) break;
 
-            mfgOk = libusb_get_string_descriptor_ascii(handle, desc.iManufacturer, buf, sizeof(buf)) >= 0;
-            if(!mfgOk) break;
+            mfgOk = libusb_get_string_descriptor_ascii(handle, desc.iManufacturer, buf, sizeof(buf));
+            if(mfgOk < 0) break;
 
             newinfo.setManufacturer(QString::fromLocal8Bit((const char*)buf));
 
-            productOk = libusb_get_string_descriptor_ascii(handle, desc.iProduct, buf, sizeof(buf)) >= 0;
-            if(!productOk) break;
+            productOk = libusb_get_string_descriptor_ascii(handle, desc.iProduct, buf, sizeof(buf));
+            if(productOk < 0) break;
 
             newinfo.setProductDescription(QString::fromLocal8Bit((const char*)buf));
 
-            serialOk = libusb_get_string_descriptor_ascii(handle, desc.iSerialNumber, buf, sizeof(buf)) >= 0;
-            if(!serialOk) break;
+            serialOk = libusb_get_string_descriptor_ascii(handle, desc.iSerialNumber, buf, sizeof(buf));
+            if(serialOk < 0) break;
 
             newinfo.setSerialNumber(QString::fromLocal8Bit((const char*)buf));
         } while(false);
 
-        if(devOk) {
+        if(devOk >= 0) {
             libusb_close(handle);
         }
 
-        if(serialOk) {
+        if(serialOk >= 0) {
             break;
         }
 
         QThread::msleep(20);
 
     } while(--numRetries);
 
-    if(!serialOk) {
-        if(!descOk) {
-            qCDebug(LOG_DETECTOR) << "Failed to get device descriptor";
-        } else if(!devOk) {
-            qCDebug(LOG_DETECTOR) << "Failed to open device";
-        } else if(!mfgOk) {
-            qCDebug(LOG_DETECTOR) << "Failed to get manufacturer string descriptor";
-        } else if(!productOk) {
-            qCDebug(LOG_DETECTOR) << "Failed to get product string descriptor";
+    if(serialOk < 0) {
+        if(descOk < 0) {
+            qCDebug(LOG_DETECTOR) << "Failed to get device descriptor:" << libusb_strerror(descOk);
+        } else if(devOk < 0) {
+            qCDebug(LOG_DETECTOR) << "Failed to open device:" << libusb_strerror(devOk);
+        } else if(mfgOk < 0) {
+            qCDebug(LOG_DETECTOR) << "Failed to get manufacturer string descriptor:" << libusb_strerror(mfgOk);
+        } else if(productOk < 0) {
+            qCDebug(LOG_DETECTOR) << "Failed to get product string descriptor:" << libusb_strerror(productOk);
         } else {
-            qCDebug(LOG_DETECTOR) << "Failed to get device serial number";
+            qCDebug(LOG_DETECTOR) << "Failed to get device serial number:" << libusb_strerror(serialOk);
         }
+        return newinfo.withBackendData(QVariant());
     }
 
     return newinfo;