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thodg/cgminer/driver-bitforce.c

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  • Author : Kano
    Date : 2013-09-14 01:20:21
    Hash : a9faec4a
    Message : change drivers to use usb_interface() - required for multi interface change

  • driver-bitforce.c
  • /*
     * Copyright 2012-2013 Andrew Smith
     * Copyright 2012 Luke Dashjr
     * Copyright 2012 Con Kolivas
     *
     * This program is free software; you can redistribute it and/or modify it
     * under the terms of the GNU General Public License as published by the Free
     * Software Foundation; either version 3 of the License, or (at your option)
     * any later version.  See COPYING for more details.
     */
    
    #include "config.h"
    
    #include <limits.h>
    #include <pthread.h>
    #include <stdint.h>
    #include <stdio.h>
    #include <strings.h>
    #include <sys/time.h>
    #include <unistd.h>
    
    #include "compat.h"
    #include "miner.h"
    #include "usbutils.h"
    #include "util.h"
    
    #ifdef WIN32
    #include <windows.h>
    #endif /* WIN32 */
    
    #define BITFORCE_IDENTIFY "ZGX"
    #define BITFORCE_IDENTIFY_LEN (sizeof(BITFORCE_IDENTIFY)-1)
    #define BITFORCE_FLASH "ZMX"
    #define BITFORCE_FLASH_LEN (sizeof(BITFORCE_FLASH)-1)
    #define BITFORCE_TEMPERATURE "ZLX"
    #define BITFORCE_TEMPERATURE_LEN (sizeof(BITFORCE_TEMPERATURE)-1)
    #define BITFORCE_SENDRANGE "ZPX"
    #define BITFORCE_SENDRANGE_LEN (sizeof(BITFORCE_SENDRANGE)-1)
    #define BITFORCE_SENDWORK "ZDX"
    #define BITFORCE_SENDWORK_LEN (sizeof(BITFORCE_SENDWORK)-1)
    #define BITFORCE_WORKSTATUS "ZFX"
    #define BITFORCE_WORKSTATUS_LEN (sizeof(BITFORCE_WORKSTATUS)-1)
    
    // Either of Nonce or No-nonce start with:
    #define BITFORCE_EITHER "N"
    #define BITFORCE_EITHER_LEN 1
    #define BITFORCE_NONCE "NONCE-FOUND"
    #define BITFORCE_NONCE_LEN (sizeof(BITFORCE_NONCE)-1)
    #define BITFORCE_NO_NONCE "NO-NONCE"
    #define BITFORCE_NO_NONCE_MATCH 3
    #define BITFORCE_IDLE "IDLE"
    #define BITFORCE_IDLE_MATCH 1
    
    #define BITFORCE_SLEEP_MS 500
    #define BITFORCE_TIMEOUT_S 7
    #define BITFORCE_TIMEOUT_MS (BITFORCE_TIMEOUT_S * 1000)
    #define BITFORCE_LONG_TIMEOUT_S 30
    #define BITFORCE_LONG_TIMEOUT_MS (BITFORCE_LONG_TIMEOUT_S * 1000)
    #define BITFORCE_CHECK_INTERVAL_MS 10
    #define WORK_CHECK_INTERVAL_MS 50
    #define MAX_START_DELAY_MS 100
    #define tv_to_ms(tval) (tval.tv_sec * 1000 + tval.tv_usec / 1000)
    #define TIME_AVG_CONSTANT 8
    
    #define KNAME_WORK  "full work"
    #define KNAME_RANGE "nonce range"
    
    #define BITFORCE_BUFSIZ (0x200)
    
    // If initialisation fails the first time,
    // sleep this amount (ms) and try again
    #define REINIT_TIME_FIRST_MS 100
    // Max ms per sleep
    #define REINIT_TIME_MAX_MS 800
    // Keep trying up to this many us
    #define REINIT_TIME_MAX 3000000
    
    static const char *blank = "";
    
    struct device_drv bitforce_drv;
    
    static void bitforce_initialise(struct cgpu_info *bitforce, bool lock)
    {
    	int err, interface;
    
    	if (lock)
    		mutex_lock(&bitforce->device_mutex);
    
    	if (bitforce->usbinfo.nodev)
    		goto failed;
    
    	interface = usb_interface(bitforce);
    	// Reset
    	err = usb_transfer(bitforce, FTDI_TYPE_OUT, FTDI_REQUEST_RESET,
    				FTDI_VALUE_RESET, interface, C_RESET);
    	if (opt_debug)
    		applog(LOG_DEBUG, "%s%i: reset got err %d",
    			bitforce->drv->name, bitforce->device_id, err);
    
    	if (bitforce->usbinfo.nodev)
    		goto failed;
    
    	// Set data control
    	err = usb_transfer(bitforce, FTDI_TYPE_OUT, FTDI_REQUEST_DATA,
    				FTDI_VALUE_DATA_BFL, interface, C_SETDATA);
    	if (opt_debug)
    		applog(LOG_DEBUG, "%s%i: setdata got err %d",
    			bitforce->drv->name, bitforce->device_id, err);
    
    	if (bitforce->usbinfo.nodev)
    		goto failed;
    
    	// Set the baud
    	err = usb_transfer(bitforce, FTDI_TYPE_OUT, FTDI_REQUEST_BAUD, FTDI_VALUE_BAUD_BFL,
    				(FTDI_INDEX_BAUD_BFL & 0xff00) | interface,
    				C_SETBAUD);
    	if (opt_debug)
    		applog(LOG_DEBUG, "%s%i: setbaud got err %d",
    			bitforce->drv->name, bitforce->device_id, err);
    
    	if (bitforce->usbinfo.nodev)
    		goto failed;
    
    	// Set Flow Control
    	err = usb_transfer(bitforce, FTDI_TYPE_OUT, FTDI_REQUEST_FLOW,
    				FTDI_VALUE_FLOW, interface, C_SETFLOW);
    	if (opt_debug)
    		applog(LOG_DEBUG, "%s%i: setflowctrl got err %d",
    			bitforce->drv->name, bitforce->device_id, err);
    
    	if (bitforce->usbinfo.nodev)
    		goto failed;
    
    	// Set Modem Control
    	err = usb_transfer(bitforce, FTDI_TYPE_OUT, FTDI_REQUEST_MODEM,
    				FTDI_VALUE_MODEM, interface, C_SETMODEM);
    	if (opt_debug)
    		applog(LOG_DEBUG, "%s%i: setmodemctrl got err %d",
    			bitforce->drv->name, bitforce->device_id, err);
    
    	if (bitforce->usbinfo.nodev)
    		goto failed;
    
    	// Clear any sent data
    	err = usb_transfer(bitforce, FTDI_TYPE_OUT, FTDI_REQUEST_RESET,
    				FTDI_VALUE_PURGE_TX, interface, C_PURGETX);
    	if (opt_debug)
    		applog(LOG_DEBUG, "%s%i: purgetx got err %d",
    			bitforce->drv->name, bitforce->device_id, err);
    
    	if (bitforce->usbinfo.nodev)
    		goto failed;
    
    	// Clear any received data
    	err = usb_transfer(bitforce, FTDI_TYPE_OUT, FTDI_REQUEST_RESET,
    				FTDI_VALUE_PURGE_RX, interface, C_PURGERX);
    	if (opt_debug)
    		applog(LOG_DEBUG, "%s%i: purgerx got err %d",
    			bitforce->drv->name, bitforce->device_id, err);
    
    failed:
    
    	if (lock)
    		mutex_unlock(&bitforce->device_mutex);
    }
    
    static bool bitforce_detect_one(struct libusb_device *dev, struct usb_find_devices *found)
    {
    	char buf[BITFORCE_BUFSIZ+1];
    	int err, amount;
    	char *s;
    	struct timeval init_start, init_now;
    	int init_sleep, init_count;
    	bool ident_first;
    
    	struct cgpu_info *bitforce = usb_alloc_cgpu(&bitforce_drv, 1);
    
    	if (!usb_init(bitforce, dev, found))
    		goto shin;
    
    	// Allow 2 complete attempts if the 1st time returns an unrecognised reply
    	ident_first = true;
    retry:
    	init_count = 0;
    	init_sleep = REINIT_TIME_FIRST_MS;
    	cgtime(&init_start);
    reinit:
    	bitforce_initialise(bitforce, false);
    	if ((err = usb_write(bitforce, BITFORCE_IDENTIFY, BITFORCE_IDENTIFY_LEN, &amount, C_REQUESTIDENTIFY)) < 0 || amount != BITFORCE_IDENTIFY_LEN) {
    		applog(LOG_ERR, "%s detect (%s) send identify request failed (%d:%d)",
    			bitforce->drv->dname, bitforce->device_path, amount, err);
    		goto unshin;
    	}
    
    	if ((err = usb_read_nl(bitforce, buf, sizeof(buf)-1, &amount, C_GETIDENTIFY)) < 0 || amount < 1) {
    		init_count++;
    		cgtime(&init_now);
    		if (us_tdiff(&init_now, &init_start) <= REINIT_TIME_MAX) {
    			if (init_count == 2) {
    				applog(LOG_WARNING, "%s detect (%s) 2nd init failed (%d:%d) - retrying",
    					bitforce->drv->dname, bitforce->device_path, amount, err);
    			}
    			cgsleep_ms(init_sleep);
    			if ((init_sleep * 2) <= REINIT_TIME_MAX_MS)
    				init_sleep *= 2;
    			goto reinit;
    		}
    
    		if (init_count > 0)
    			applog(LOG_WARNING, "%s detect (%s) init failed %d times %.2fs",
    				bitforce->drv->dname, bitforce->device_path, init_count, tdiff(&init_now, &init_start));
    
    		if (err < 0) {
    			applog(LOG_ERR, "%s detect (%s) error identify reply (%d:%d)",
    				bitforce->drv->dname, bitforce->device_path, amount, err);
    		} else {
    			applog(LOG_ERR, "%s detect (%s) empty identify reply (%d)",
    				bitforce->drv->dname, bitforce->device_path, amount);
    		}
    
    		goto unshin;
    	}
    	buf[amount] = '\0';
    
    	if (unlikely(!strstr(buf, "SHA256"))) {
    		if (ident_first) {
    			applog(LOG_WARNING, "%s detect (%s) didn't recognise '%s' trying again ...",
    				bitforce->drv->dname, bitforce->device_path, buf);
    			ident_first = false;
    			goto retry;
    		}
    		applog(LOG_ERR, "%s detect (%s) didn't recognise '%s' on 2nd attempt",
    			bitforce->drv->dname, bitforce->device_path, buf);
    		goto unshin;
    	}
    
    	if (strstr(buf, "SHA256 SC")) {
    #ifdef USE_BFLSC
    		applog(LOG_DEBUG, "SC device detected, will defer to BFLSC driver");
    #else
    		applog(LOG_WARNING, "SC device detected but no BFLSC support compiled in!");
    #endif
    		goto unshin;
    	}
    
    	if (likely((!memcmp(buf, ">>>ID: ", 7)) && (s = strstr(buf + 3, ">>>")))) {
    		s[0] = '\0';
    		bitforce->name = strdup(buf + 7);
    	} else {
    		bitforce->name = (char *)blank;
    	}
    
    	// We have a real BitForce!
    	applog(LOG_DEBUG, "%s (%s) identified as: '%s'",
    		bitforce->drv->dname, bitforce->device_path, bitforce->name);
    
    	/* Initially enable support for nonce range and disable it later if it
    	 * fails */
    	if (opt_bfl_noncerange) {
    		bitforce->nonce_range = true;
    		bitforce->sleep_ms = BITFORCE_SLEEP_MS;
    		bitforce->kname = KNAME_RANGE;
    	} else {
    		bitforce->sleep_ms = BITFORCE_SLEEP_MS * 5;
    		bitforce->kname = KNAME_WORK;
    	}
    
    	if (!add_cgpu(bitforce))
    		goto unshin;
    
    	update_usb_stats(bitforce);
    
    	mutex_init(&bitforce->device_mutex);
    
    	return true;
    
    unshin:
    
    	usb_uninit(bitforce);
    
    shin:
    
    	if (bitforce->name != blank) {
    		free(bitforce->name);
    		bitforce->name = NULL;
    	}
    
    	bitforce = usb_free_cgpu(bitforce);
    
    	return false;
    }
    
    static void bitforce_detect(void)
    {
    	usb_detect(&bitforce_drv, bitforce_detect_one);
    }
    
    static void get_bitforce_statline_before(char *buf, size_t bufsiz, struct cgpu_info *bitforce)
    {
    	float gt = bitforce->temp;
    
    	if (gt > 0)
    		tailsprintf(buf, bufsiz, "%5.1fC ", gt);
    	else
    		tailsprintf(buf, bufsiz, "       ");
    
    	tailsprintf(buf, bufsiz, "        | ");
    }
    
    static bool bitforce_thread_prepare(__maybe_unused struct thr_info *thr)
    {
    //	struct cgpu_info *bitforce = thr->cgpu;
    
    	return true;
    }
    
    static void bitforce_flash_led(struct cgpu_info *bitforce)
    {
    	int err, amount;
    
    	/* Do not try to flash the led if we're polling for a result to
    	 * minimise the chance of interleaved results */
    	if (bitforce->polling)
    		return;
    
    	/* It is not critical flashing the led so don't get stuck if we
    	 * can't grab the mutex now */
    	if (mutex_trylock(&bitforce->device_mutex))
    		return;
    
    	if ((err = usb_write(bitforce, BITFORCE_FLASH, BITFORCE_FLASH_LEN, &amount, C_REQUESTFLASH)) < 0 || amount != BITFORCE_FLASH_LEN) {
    		applog(LOG_ERR, "%s%i: flash request failed (%d:%d)",
    			bitforce->drv->name, bitforce->device_id, amount, err);
    	} else {
    		/* However, this stops anything else getting a reply
    		 * So best to delay any other access to the BFL */
    		cgsleep_ms(4000);
    	}
    
    	/* Once we've tried - don't do it until told to again */
    	bitforce->flash_led = false;
    
    	mutex_unlock(&bitforce->device_mutex);
    
    	return; // nothing is returned by the BFL
    }
    
    static bool bitforce_get_temp(struct cgpu_info *bitforce)
    {
    	char buf[BITFORCE_BUFSIZ+1];
    	int err, amount;
    	char *s;
    
    	// Device is gone
    	if (bitforce->usbinfo.nodev)
    		return false;
    
    	/* Do not try to get the temperature if we're polling for a result to
    	 * minimise the chance of interleaved results */
    	if (bitforce->polling)
    		return true;
    
    	// Flash instead of Temp - doing both can be too slow
    	if (bitforce->flash_led) {
    		bitforce_flash_led(bitforce);
     		return true;
    	}
    
    	/* It is not critical getting temperature so don't get stuck if we
    	 * can't grab the mutex here */
    	if (mutex_trylock(&bitforce->device_mutex))
    		return false;
    
    	if ((err = usb_write(bitforce, BITFORCE_TEMPERATURE, BITFORCE_TEMPERATURE_LEN, &amount, C_REQUESTTEMPERATURE)) < 0 || amount != BITFORCE_TEMPERATURE_LEN) {
    		mutex_unlock(&bitforce->device_mutex);
    		applog(LOG_ERR, "%s%i: Error: Request temp invalid/timed out (%d:%d)",
    				bitforce->drv->name, bitforce->device_id, amount, err);
    		bitforce->hw_errors++;
    		return false;
    	}
    
    	if ((err = usb_read_nl(bitforce, buf, sizeof(buf)-1, &amount, C_GETTEMPERATURE)) < 0 || amount < 1) {
    		mutex_unlock(&bitforce->device_mutex);
    		if (err < 0) {
    			applog(LOG_ERR, "%s%i: Error: Get temp return invalid/timed out (%d:%d)",
    					bitforce->drv->name, bitforce->device_id, amount, err);
    		} else {
    			applog(LOG_ERR, "%s%i: Error: Get temp returned nothing (%d:%d)",
    					bitforce->drv->name, bitforce->device_id, amount, err);
    		}
    		bitforce->hw_errors++;
    		return false;
    	}
    
    	mutex_unlock(&bitforce->device_mutex);
    	
    	if ((!strncasecmp(buf, "TEMP", 4)) && (s = strchr(buf + 4, ':'))) {
    		float temp = strtof(s + 1, NULL);
    
    		/* Cope with older software  that breaks and reads nonsense
    		 * values */
    		if (temp > 100)
    			temp = strtod(s + 1, NULL);
    
    		if (temp > 0) {
    			bitforce->temp = temp;
    			if (unlikely(bitforce->cutofftemp > 0 && temp > bitforce->cutofftemp)) {
    				applog(LOG_WARNING, "%s%i: Hit thermal cutoff limit, disabling!",
    							bitforce->drv->name, bitforce->device_id);
    				bitforce->deven = DEV_RECOVER;
    				dev_error(bitforce, REASON_DEV_THERMAL_CUTOFF);
    			}
    		}
    	} else {
    		/* Use the temperature monitor as a kind of watchdog for when
    		 * our responses are out of sync and flush the buffer to
    		 * hopefully recover */
    		applog(LOG_WARNING, "%s%i: Garbled response probably throttling, clearing buffer",
    					bitforce->drv->name, bitforce->device_id);
    		dev_error(bitforce, REASON_DEV_THROTTLE);
    		/* Count throttling episodes as hardware errors */
    		bitforce->hw_errors++;
    		bitforce_initialise(bitforce, true);
    		return false;
    	}
    
    	return true;
    }
    
    static bool bitforce_send_work(struct thr_info *thr, struct work *work)
    {
    	struct cgpu_info *bitforce = thr->cgpu;
    	unsigned char ob[70];
    	char buf[BITFORCE_BUFSIZ+1];
    	int err, amount;
    	char *s;
    	char *cmd;
    	int len;
    
    re_send:
    	if (bitforce->nonce_range) {
    		cmd = BITFORCE_SENDRANGE;
    		len = BITFORCE_SENDRANGE_LEN;
    	} else {
    		cmd = BITFORCE_SENDWORK;
    		len = BITFORCE_SENDWORK_LEN;
    	}
    
    	mutex_lock(&bitforce->device_mutex);
    	if ((err = usb_write(bitforce, cmd, len, &amount, C_REQUESTSENDWORK)) < 0 || amount != len) {
    		mutex_unlock(&bitforce->device_mutex);
    		applog(LOG_ERR, "%s%i: request send work failed (%d:%d)",
    				bitforce->drv->name, bitforce->device_id, amount, err);
    		return false;
    	}
    
    	if ((err = usb_read_nl(bitforce, buf, sizeof(buf)-1, &amount, C_REQUESTSENDWORKSTATUS)) < 0) {
    		mutex_unlock(&bitforce->device_mutex);
    		applog(LOG_ERR, "%s%d: read request send work status failed (%d:%d)",
    				bitforce->drv->name, bitforce->device_id, amount, err);
    		return false;
    	}
    
    	if (amount == 0 || !buf[0] || !strncasecmp(buf, "B", 1)) {
    		mutex_unlock(&bitforce->device_mutex);
    		cgsleep_ms(WORK_CHECK_INTERVAL_MS);
    		goto re_send;
    	} else if (unlikely(strncasecmp(buf, "OK", 2))) {
    		mutex_unlock(&bitforce->device_mutex);
    		if (bitforce->nonce_range) {
    			applog(LOG_WARNING, "%s%i: Does not support nonce range, disabling",
    						bitforce->drv->name, bitforce->device_id);
    			bitforce->nonce_range = false;
    			bitforce->sleep_ms *= 5;
    			bitforce->kname = KNAME_WORK;
    			goto re_send;
    		}
    		applog(LOG_ERR, "%s%i: Error: Send work reports: %s",
    				bitforce->drv->name, bitforce->device_id, buf);
    		return false;
    	}
    
    	sprintf((char *)ob, ">>>>>>>>");
    	memcpy(ob + 8, work->midstate, 32);
    	memcpy(ob + 8 + 32, work->data + 64, 12);
    	if (!bitforce->nonce_range) {
    		sprintf((char *)ob + 8 + 32 + 12, ">>>>>>>>");
    		work->blk.nonce = bitforce->nonces = 0xffffffff;
    		len = 60;
    	} else {
    		uint32_t *nonce;
    
    		nonce = (uint32_t *)(ob + 8 + 32 + 12);
    		*nonce = htobe32(work->blk.nonce);
    		nonce = (uint32_t *)(ob + 8 + 32 + 12 + 4);
    		/* Split work up into 1/5th nonce ranges */
    		bitforce->nonces = 0x33333332;
    		*nonce = htobe32(work->blk.nonce + bitforce->nonces);
    		work->blk.nonce += bitforce->nonces + 1;
    		sprintf((char *)ob + 8 + 32 + 12 + 8, ">>>>>>>>");
    		len = 68;
    	}
    
    	if ((err = usb_write(bitforce, (char *)ob, len, &amount, C_SENDWORK)) < 0 || amount != len) {
    		mutex_unlock(&bitforce->device_mutex);
    		applog(LOG_ERR, "%s%i: send work failed (%d:%d)",
    				bitforce->drv->name, bitforce->device_id, amount, err);
    		return false;
    	}
    
    	if ((err = usb_read_nl(bitforce, buf, sizeof(buf)-1, &amount, C_SENDWORKSTATUS)) < 0) {
    		mutex_unlock(&bitforce->device_mutex);
    		applog(LOG_ERR, "%s%d: read send work status failed (%d:%d)",
    				bitforce->drv->name, bitforce->device_id, amount, err);
    		return false;
    	}
    
    	mutex_unlock(&bitforce->device_mutex);
    
    	if (opt_debug) {
    		s = bin2hex(ob + 8, 44);
    		applog(LOG_DEBUG, "%s%i: block data: %s",
    				bitforce->drv->name, bitforce->device_id, s);
    		free(s);
    	}
    
    	if (amount == 0 || !buf[0]) {
    		applog(LOG_ERR, "%s%i: Error: Send block data returned empty string/timed out",
    				bitforce->drv->name, bitforce->device_id);
    		return false;
    	}
    
    	if (unlikely(strncasecmp(buf, "OK", 2))) {
    		applog(LOG_ERR, "%s%i: Error: Send block data reports: %s",
    				bitforce->drv->name, bitforce->device_id, buf);
    		return false;
    	}
    
    	cgtime(&bitforce->work_start_tv);
    	return true;
    }
    
    static int64_t bitforce_get_result(struct thr_info *thr, struct work *work)
    {
    	struct cgpu_info *bitforce = thr->cgpu;
    	unsigned int delay_time_ms;
    	struct timeval elapsed;
    	struct timeval now;
    	char buf[BITFORCE_BUFSIZ+1];
    	int amount;
    	char *pnoncebuf;
    	uint32_t nonce;
    
    	while (1) {
    		if (unlikely(thr->work_restart))
    			return 0;
    
    		mutex_lock(&bitforce->device_mutex);
    		usb_write(bitforce, BITFORCE_WORKSTATUS, BITFORCE_WORKSTATUS_LEN, &amount, C_REQUESTWORKSTATUS);
    		usb_read_nl(bitforce, buf, sizeof(buf)-1, &amount, C_GETWORKSTATUS);
    		mutex_unlock(&bitforce->device_mutex);
    
    		cgtime(&now);
    		timersub(&now, &bitforce->work_start_tv, &elapsed);
    
    		if (elapsed.tv_sec >= BITFORCE_LONG_TIMEOUT_S) {
    			applog(LOG_ERR, "%s%i: took %ldms - longer than %dms",
    				bitforce->drv->name, bitforce->device_id,
    				tv_to_ms(elapsed), BITFORCE_LONG_TIMEOUT_MS);
    			return 0;
    		}
    
    		if (amount > 0 && buf[0] && strncasecmp(buf, "B", 1)) /* BFL does not respond during throttling */
    			break;
    
    		/* if BFL is throttling, no point checking so quickly */
    		delay_time_ms = (buf[0] ? BITFORCE_CHECK_INTERVAL_MS : 2 * WORK_CHECK_INTERVAL_MS);
    		cgsleep_ms(delay_time_ms);
    		bitforce->wait_ms += delay_time_ms;
    	}
    
    	if (elapsed.tv_sec > BITFORCE_TIMEOUT_S) {
    		applog(LOG_ERR, "%s%i: took %ldms - longer than %dms",
    			bitforce->drv->name, bitforce->device_id,
    			tv_to_ms(elapsed), BITFORCE_TIMEOUT_MS);
    		dev_error(bitforce, REASON_DEV_OVER_HEAT);
    
    		/* Only return if we got nothing after timeout - there still may be results */
    		if (amount == 0)
    			return 0;
    	} else if (!strncasecmp(buf, BITFORCE_EITHER, BITFORCE_EITHER_LEN)) {
    		/* Simple timing adjustment. Allow a few polls to cope with
    		 * OS timer delays being variably reliable. wait_ms will
    		 * always equal sleep_ms when we've waited greater than or
    		 * equal to the result return time.*/
    		delay_time_ms = bitforce->sleep_ms;
    
    		if (bitforce->wait_ms > bitforce->sleep_ms + (WORK_CHECK_INTERVAL_MS * 2))
    			bitforce->sleep_ms += (bitforce->wait_ms - bitforce->sleep_ms) / 2;
    		else if (bitforce->wait_ms == bitforce->sleep_ms) {
    			if (bitforce->sleep_ms > WORK_CHECK_INTERVAL_MS)
    				bitforce->sleep_ms -= WORK_CHECK_INTERVAL_MS;
    			else if (bitforce->sleep_ms > BITFORCE_CHECK_INTERVAL_MS)
    				bitforce->sleep_ms -= BITFORCE_CHECK_INTERVAL_MS;
    		}
    
    		if (delay_time_ms != bitforce->sleep_ms)
    			  applog(LOG_DEBUG, "%s%i: Wait time changed to: %d, waited %u",
    					bitforce->drv->name, bitforce->device_id,
    					bitforce->sleep_ms, bitforce->wait_ms);
    
    		/* Work out the average time taken. Float for calculation, uint for display */
    		bitforce->avg_wait_f += (tv_to_ms(elapsed) - bitforce->avg_wait_f) / TIME_AVG_CONSTANT;
    		bitforce->avg_wait_d = (unsigned int) (bitforce->avg_wait_f + 0.5);
    	}
    
    	applog(LOG_DEBUG, "%s%i: waited %dms until %s",
    			bitforce->drv->name, bitforce->device_id,
    			bitforce->wait_ms, buf);
    	if (!strncasecmp(buf, BITFORCE_NO_NONCE, BITFORCE_NO_NONCE_MATCH))
    		return bitforce->nonces;   /* No valid nonce found */
    	else if (!strncasecmp(buf, BITFORCE_IDLE, BITFORCE_IDLE_MATCH))
    		return 0;	/* Device idle */
    	else if (strncasecmp(buf, BITFORCE_NONCE, BITFORCE_NONCE_LEN)) {
    		bitforce->hw_errors++;
    		applog(LOG_WARNING, "%s%i: Error: Get result reports: %s",
    			bitforce->drv->name, bitforce->device_id, buf);
    		bitforce_initialise(bitforce, true);
    		return 0;
    	}
    
    	pnoncebuf = &buf[12];
    
    	while (1) {
    		hex2bin((void*)&nonce, pnoncebuf, 4);
    #ifndef __BIG_ENDIAN__
    		nonce = swab32(nonce);
    #endif
    		if (unlikely(bitforce->nonce_range && (nonce >= work->blk.nonce ||
    			(work->blk.nonce > 0 && nonce < work->blk.nonce - bitforce->nonces - 1)))) {
    				applog(LOG_WARNING, "%s%i: Disabling broken nonce range support",
    					bitforce->drv->name, bitforce->device_id);
    				bitforce->nonce_range = false;
    				work->blk.nonce = 0xffffffff;
    				bitforce->sleep_ms *= 5;
    				bitforce->kname = KNAME_WORK;
    		}
    			
    		submit_nonce(thr, work, nonce);
    		if (strncmp(&pnoncebuf[8], ",", 1))
    			break;
    		pnoncebuf += 9;
    	}
    
    	return bitforce->nonces;
    }
    
    static void bitforce_shutdown(__maybe_unused struct thr_info *thr)
    {
    //	struct cgpu_info *bitforce = thr->cgpu;
    }
    
    static void biforce_thread_enable(struct thr_info *thr)
    {
    	struct cgpu_info *bitforce = thr->cgpu;
    
    	bitforce_initialise(bitforce, true);
    }
    
    static int64_t bitforce_scanhash(struct thr_info *thr, struct work *work, int64_t __maybe_unused max_nonce)
    {
    	struct cgpu_info *bitforce = thr->cgpu;
    	bool send_ret;
    	int64_t ret;
    
    	// Device is gone
    	if (bitforce->usbinfo.nodev)
    		return -1;
    
    	send_ret = bitforce_send_work(thr, work);
    
    	if (!restart_wait(thr, bitforce->sleep_ms))
    		return 0;
    
    	bitforce->wait_ms = bitforce->sleep_ms;
    
    	if (send_ret) {
    		bitforce->polling = true;
    		ret = bitforce_get_result(thr, work);
    		bitforce->polling = false;
    	} else
    		ret = -1;
    
    	if (ret == -1) {
    		ret = 0;
    		applog(LOG_ERR, "%s%i: Comms error", bitforce->drv->name, bitforce->device_id);
    		dev_error(bitforce, REASON_DEV_COMMS_ERROR);
    		bitforce->hw_errors++;
    		/* empty read buffer */
    		bitforce_initialise(bitforce, true);
    	}
    	return ret;
    }
    
    static bool bitforce_get_stats(struct cgpu_info *bitforce)
    {
    	return bitforce_get_temp(bitforce);
    }
    
    static void bitforce_identify(struct cgpu_info *bitforce)
    {
    	bitforce->flash_led = true;
    }
    
    static bool bitforce_thread_init(struct thr_info *thr)
    {
    	struct cgpu_info *bitforce = thr->cgpu;
    	unsigned int wait;
    
    	/* Pause each new thread at least 100ms between initialising
    	 * so the devices aren't making calls all at the same time. */
    	wait = thr->id * MAX_START_DELAY_MS;
    	applog(LOG_DEBUG, "%s%d: Delaying start by %dms",
    			bitforce->drv->name, bitforce->device_id, wait / 1000);
    	cgsleep_ms(wait);
    
    	return true;
    }
    
    static struct api_data *bitforce_api_stats(struct cgpu_info *cgpu)
    {
    	struct api_data *root = NULL;
    
    	// Warning, access to these is not locked - but we don't really
    	// care since hashing performance is way more important than
    	// locking access to displaying API debug 'stats'
    	// If locking becomes an issue for any of them, use copy_data=true also
    	root = api_add_uint(root, "Sleep Time", &(cgpu->sleep_ms), false);
    	root = api_add_uint(root, "Avg Wait", &(cgpu->avg_wait_d), false);
    
    	return root;
    }
    
    struct device_drv bitforce_drv = {
    	.drv_id = DRIVER_BITFORCE,
    	.dname = "BitForce",
    	.name = "BFL",
    	.drv_detect = bitforce_detect,
    	.get_api_stats = bitforce_api_stats,
    	.get_statline_before = get_bitforce_statline_before,
    	.get_stats = bitforce_get_stats,
    	.identify_device = bitforce_identify,
    	.thread_prepare = bitforce_thread_prepare,
    	.thread_init = bitforce_thread_init,
    	.scanhash = bitforce_scanhash,
    	.thread_shutdown = bitforce_shutdown,
    	.thread_enable = biforce_thread_enable
    };