xum1541_init(): only configure device if not already done

thierer · May 21, 2020 · 88f2a70 · 88f2a70
1 parent bd17972
commit 88f2a70
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Showing 3 changed files with 17 additions and 2 deletions.
diff --git a/opencbm/lib/plugin/xum1541/xum1541.c b/opencbm/lib/plugin/xum1541/xum1541.c
@@ -552,13 +552,26 @@ xum1541_init(struct opencbm_usb_handle **HandleXum1541_p, int PortNumber)
     }
 
     do {
-        // Select first and only device configuration.
-        ret = usb.set_configuration(HandleXum1541->devh, 1);
+        int config = 0;
+
+        // Check if device is already configured
+        ret = usb.get_configuration(HandleXum1541->devh, &config);
         if (ret != LIBUSB_SUCCESS) {
             xum1541_cleanup(HandleXum1541, "USB error: %s\n", usb.error_name(ret));
             break;
         }
 
+        if (config == 0) {
+            // Select first and only device configuration.
+            ret = usb.set_configuration(HandleXum1541->devh, 1);
+            if (ret != LIBUSB_SUCCESS) {
+                xum1541_cleanup(HandleXum1541, "USB error: %s\n", usb.error_name(ret));
+                break;
+            }
+        } else {
+            fprintf(stderr, "Device already configured (%d), skipping set_configuration()\n", config);
+        }
+
         /*
          * Get exclusive access to interface 0.
          * After this point, do cleanup using xum1541_close() instead of

diff --git a/opencbm/libmisc/LINUX/dynlibusb.c b/opencbm/libmisc/LINUX/dynlibusb.c
@@ -39,6 +39,7 @@ usb_dll_t usb = {
     .bulk_transfer = libusb_bulk_transfer,
     .control_transfer = libusb_control_transfer,
     .set_configuration = libusb_set_configuration,
+    .get_configuration = libusb_get_configuration,
     .claim_interface = libusb_claim_interface,
     .release_interface = libusb_release_interface,
     .clear_halt = libusb_clear_halt,

diff --git a/opencbm/libmisc/dynlibusb.h b/opencbm/libmisc/dynlibusb.h
@@ -52,6 +52,7 @@ struct usb_dll_s {
     int (LIBUSB_APIDECL *control_transfer)(libusb_device_handle *dev_handle, uint8_t request_type, uint8_t bRequest, uint16_t wValue, uint16_t wIndex, unsigned char *data, uint16_t wLength, unsigned int timeout);
 
     int (LIBUSB_APIDECL *set_configuration)(libusb_device_handle *dev, int configuration);
+    int (LIBUSB_APIDECL *get_configuration)(libusb_device_handle *dev, int *configuration);
     int (LIBUSB_APIDECL *claim_interface)(libusb_device_handle *dev, int interface);
     int (LIBUSB_APIDECL *release_interface)(libusb_device_handle *dev, int interface);
     int (LIBUSB_APIDECL *clear_halt)(libusb_device_handle *dev, unsigned char ep);