Use an int for usb_read/write to identify overruns.

usbutils.c

@@ -2484,7 +2484,7 @@ usb_bulk_transfer(struct libusb_device_handle *dev_handle, int intinfo,
 	return err;
 }
 
-int _usb_read(struct cgpu_info *cgpu, int intinfo, int epinfo, char *buf, size_t bufsiz, int *processed, unsigned int timeout, const char *end, enum usb_cmds cmd, bool readonce, bool cancellable)
+int _usb_read(struct cgpu_info *cgpu, int intinfo, int epinfo, char *buf, size_t bufsiz, int *processed, int timeout, const char *end, enum usb_cmds cmd, bool readonce, bool cancellable)
 {
 	struct cg_usb_device *usbdev;
 	bool ftdi;
@@ -2731,7 +2731,7 @@ out_noerrmsg:
 	return err;
 }
 
-int _usb_write(struct cgpu_info *cgpu, int intinfo, int epinfo, char *buf, size_t bufsiz, int *processed, unsigned int timeout, enum usb_cmds cmd)
+int _usb_write(struct cgpu_info *cgpu, int intinfo, int epinfo, char *buf, size_t bufsiz, int *processed, int timeout, enum usb_cmds cmd)
 {
 	struct cg_usb_device *usbdev;
 	struct timeval read_start, tv_finish;

usbutils.h

@@ -388,8 +388,8 @@ bool usb_init(struct cgpu_info *cgpu, struct libusb_device *dev, struct usb_find
 void usb_detect(struct device_drv *drv, bool (*device_detect)(struct libusb_device *, struct usb_find_devices *));
 struct api_data *api_usb_stats(int *count);
 void update_usb_stats(struct cgpu_info *cgpu);
-int _usb_read(struct cgpu_info *cgpu, int intinfo, int epinfo, char *buf, size_t bufsiz, int *processed, unsigned int timeout, const char *end, enum usb_cmds cmd, bool readonce, bool cancellable);
-int _usb_write(struct cgpu_info *cgpu, int intinfo, int epinfo, char *buf, size_t bufsiz, int *processed, unsigned int timeout, enum usb_cmds);
+int _usb_read(struct cgpu_info *cgpu, int intinfo, int epinfo, char *buf, size_t bufsiz, int *processed, int timeout, const char *end, enum usb_cmds cmd, bool readonce, bool cancellable);
+int _usb_write(struct cgpu_info *cgpu, int intinfo, int epinfo, char *buf, size_t bufsiz, int *processed, int timeout, enum usb_cmds);
 int _usb_transfer(struct cgpu_info *cgpu, uint8_t request_type, uint8_t bRequest, uint16_t wValue, uint16_t wIndex, uint32_t *data, int siz, unsigned int timeout, enum usb_cmds cmd);
 int _usb_transfer_read(struct cgpu_info *cgpu, uint8_t request_type, uint8_t bRequest, uint16_t wValue, uint16_t wIndex, char *buf, int bufsiz, int *amount, unsigned int timeout, enum usb_cmds cmd);
 int usb_ftdi_cts(struct cgpu_info *cgpu);