reset device before every connection

We reset a usb device before issuing LIBMTP_Open_Raw_Device_Uncached(), so we do not timeout, when libmtp can't properly open the usb device.

src/simple-mtpfs-mtp-device.cpp

@@ -94,9 +94,18 @@ bool MTPDevice::connect(int dev_no)
         return false;
     }
 
+    LIBMTP_raw_device_t *raw_device = &raw_devices[dev_no];
+
+#ifdef HAVE_LIBUSB1
+    // Try to reset USB device, so we don't wait until LIBMTP times out.
+    // We do this every time we are about to mount a device, but better
+    // connect on first try, than wait for 60s timeout.
+    smtpfs_reset_device(raw_device);
+#endif // HAVE_LIBUSB1
+
     // Do not output LIBMTP debug stuff
     StreamHelper::off();
-    m_device = LIBMTP_Open_Raw_Device_Uncached(&raw_devices[dev_no]);
+    m_device = LIBMTP_Open_Raw_Device_Uncached(raw_device);
     StreamHelper::on();
     free(static_cast<void*>(raw_devices));
 
@@ -120,17 +129,24 @@ bool MTPDevice::connect(const std::string &dev_file)
         return true;
     }
 
-    LIBMTP_raw_device_t *device = smtpfs_raw_device_new(dev_file);
-    if (!device) {
+    LIBMTP_raw_device_t *raw_device = smtpfs_raw_device_new(dev_file);
+    if (!raw_device) {
         logerr("Can not open such device '", dev_file, "'.\n");
         return false;
     }
 
+#ifdef HAVE_LIBUSB1
+    // Try to reset USB device, so we don't wait until LIBMTP times out.
+    // We do this every time we are about to mount a device, but better
+    // connect on first try, than wait for 60s timeout.
+    smtpfs_reset_device(raw_device);
+#endif // HAVE_LIBUSB1
+
     // Do not output LIBMTP debug stuff
     StreamHelper::off();
-    m_device = LIBMTP_Open_Raw_Device_Uncached(device);
+    m_device = LIBMTP_Open_Raw_Device_Uncached(raw_device);
     StreamHelper::on();
-    smtpfs_raw_device_free(device);
+    smtpfs_raw_device_free(raw_device);
 
     if (!m_device) {
         LIBMTP_Dump_Errorstack(m_device);

src/simple-mtpfs-util.cpp

@@ -37,6 +37,7 @@ extern "C" {
 #  include <libusb.h>
 }
 #endif // HAVE_LIBUSB1
+#include "simple-mtpfs-log.h"
 #include "simple-mtpfs-util.h"
 
 const std::string devnull = "/dev/null";
@@ -227,6 +228,39 @@ LIBMTP_raw_device_t *smtpfs_raw_device_new(const std::string &path)
     return raw_device;
 }
 
+bool smtpfs_reset_device(LIBMTP_raw_device_t *device)
+{
+    if (libusb_init(NULL) != 0)
+        return false;
+
+    libusb_device **dev_list;
+    ssize_t num_devs = libusb_get_device_list(NULL, &dev_list);
+    if (!num_devs) {
+        libusb_exit(NULL);
+        return false;
+    }
+
+    libusb_device_handle *dev_handle = nullptr;
+    for (auto i = 0; i < num_devs; ++i) {
+        uint8_t bnum = libusb_get_bus_number(dev_list[i]);
+        uint8_t dnum = libusb_get_device_address(dev_list[i]);
+
+        if (static_cast<uint32_t>(bnum) == device->bus_location &&
+            dnum == device->devnum)
+        {
+            libusb_open(dev_list[i], &dev_handle);
+            libusb_reset_device(dev_handle);
+            libusb_close(dev_handle);
+            break;
+        }
+    }
+
+    libusb_free_device_list(dev_list, 0);
+    libusb_exit(NULL);
+
+    return true;
+}
+
 void smtpfs_raw_device_free(LIBMTP_raw_device_t *device)
 {
     if (!device)

src/simple-mtpfs-util.h

@@ -51,6 +51,7 @@ bool smtpfs_check_dir(const std::string &path);
 #ifdef HAVE_LIBUSB1
 LIBMTP_raw_device_t *smtpfs_raw_device_new(const std::string &path);
 void smtpfs_raw_device_free(LIBMTP_raw_device_t *device);
+bool smtpfs_reset_device(LIBMTP_raw_device_t *device);
 #endif // HAVE_LIBUSB1
 
 #endif // SIMPLE_MTPFS_UTIL