sysclk-lwla: Set USB device configuration

After opening the USB device, set the device configuration to 1.
Actually, do it twice, just as the vendor driver seems to do. This
is supposed to trigger a lightweight reset of the device.

Originally, I omitted this reset sequence from the sigrok driver
because it simply did not work at all for me. However, it does seem
to work now, so that may have been a problem in libusb or the kernel
which is now fixed.

With some luck, this change may finally fix #327.

diff --git a/src/hardware/sysclk-lwla/api.c b/src/hardware/sysclk-lwla/api.c
index cee779eb4820861e6cf5a68de2cbfc810ddd21d4..154d4f9000ee6247fb583f78eee49b93e0febbb5 100644 (file)
--- a/src/hardware/sysclk-lwla/api.c
+++ b/src/hardware/sysclk-lwla/api.c
@@ -203,6 +203,18 @@ static int dev_open(struct sr_dev_inst *sdi)
        if (ret != SR_OK)
                return ret;
 
+       /* Set the configuration twice to trigger a lightweight reset.
+        */
+       ret = libusb_set_configuration(usb->devhdl, USB_CONFIG);
+       if (ret == 0)
+               ret = libusb_set_configuration(usb->devhdl, USB_CONFIG);
+       if (ret != 0) {
+               sr_err("Failed to set USB configuration: %s.",
+                       libusb_error_name(ret));
+               sr_usb_close(usb);
+               return SR_ERR;
+       }
+
        ret = libusb_claim_interface(usb->devhdl, USB_INTERFACE);
        if (ret < 0) {
                sr_err("Failed to claim interface: %s.",

diff --git a/src/hardware/sysclk-lwla/protocol.h b/src/hardware/sysclk-lwla/protocol.h
index ce489f71810b81fe3e66ed637be736865e174aee..aedac6ee325374212827fbacbf4ef98b1287fbcd 100644 (file)
--- a/src/hardware/sysclk-lwla/protocol.h
+++ b/src/hardware/sysclk-lwla/protocol.h
@@ -34,6 +34,7 @@
 #define MODEL_NAME     "LWLA1034"
 
 #define USB_VID_PID    "2961.6689"
+#define USB_CONFIG     1
 #define USB_INTERFACE  0
 #define USB_TIMEOUT_MS 3000