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thodg/cgminer/driver-icarus.c

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  • Author : Paul Sheppard
    Date : 2012-11-04 20:13:49
    Hash : 9f74e650
    Message : Tidy up device error counts

  • driver-icarus.c
  • /*
     * Copyright 2012 Luke Dashjr
     * Copyright 2012 Xiangfu <xiangfu@openmobilefree.com>
     * Copyright 2012 Andrew Smith
     *
     * 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.
     */
    
    /*
     * Those code should be works fine with V2 and V3 bitstream of Icarus.
     * Operation:
     *   No detection implement.
     *   Input: 64B = 32B midstate + 20B fill bytes + last 12 bytes of block head.
     *   Return: send back 32bits immediately when Icarus found a valid nonce.
     *           no query protocol implemented here, if no data send back in ~11.3
     *           seconds (full cover time on 32bit nonce range by 380MH/s speed)
     *           just send another work.
     * Notice:
     *   1. Icarus will start calculate when you push a work to them, even they
     *      are busy.
     *   2. The 2 FPGAs on Icarus will distribute the job, one will calculate the
     *      0 ~ 7FFFFFFF, another one will cover the 80000000 ~ FFFFFFFF.
     *   3. It's possible for 2 FPGAs both find valid nonce in the meantime, the 2
     *      valid nonce will all be send back.
     *   4. Icarus will stop work when: a valid nonce has been found or 32 bits
     *      nonce range is completely calculated.
     */
    
    #include "config.h"
    
    #include <limits.h>
    #include <pthread.h>
    #include <stdio.h>
    #include <sys/time.h>
    #include <sys/types.h>
    #include <dirent.h>
    #include <unistd.h>
    #ifndef WIN32
      #include <termios.h>
      #include <sys/stat.h>
      #include <fcntl.h>
      #ifndef O_CLOEXEC
        #define O_CLOEXEC 0
      #endif
    #else
      #include <windows.h>
      #include <io.h>
    #endif
    
    #include "elist.h"
    #include "miner.h"
    #include "fpgautils.h"
    
    // The serial I/O speed - Linux uses a define 'B115200' in bits/termios.h
    #define ICARUS_IO_SPEED 115200
    
    // The size of a successful nonce read
    #define ICARUS_READ_SIZE 4
    
    // Ensure the sizes are correct for the Serial read
    #if (ICARUS_READ_SIZE != 4)
    #error ICARUS_READ_SIZE must be 4
    #endif
    #define ASSERT1(condition) __maybe_unused static char sizeof_uint32_t_must_be_4[(condition)?1:-1]
    ASSERT1(sizeof(uint32_t) == 4);
    
    #define ICARUS_READ_TIME(baud) ((double)ICARUS_READ_SIZE * (double)8.0 / (double)(baud))
    
    // Fraction of a second, USB timeout is measured in
    // i.e. 10 means 1/10 of a second
    #define TIME_FACTOR 10
    // It's 10 per second, thus value = 10/TIME_FACTOR =
    #define ICARUS_READ_FAULT_DECISECONDS 1
    
    // In timing mode: Default starting value until an estimate can be obtained
    // 5 seconds allows for up to a ~840MH/s device
    #define ICARUS_READ_COUNT_TIMING	(5 * TIME_FACTOR)
    
    // For a standard Icarus REV3 (to 5 places)
    // Since this rounds up a the last digit - it is a slight overestimate
    // Thus the hash rate will be a VERY slight underestimate
    // (by a lot less than the displayed accuracy)
    #define ICARUS_REV3_HASH_TIME 0.0000000026316
    #define NANOSEC 1000000000.0
    
    // Icarus Rev3 doesn't send a completion message when it finishes
    // the full nonce range, so to avoid being idle we must abort the
    // work (by starting a new work) shortly before it finishes
    //
    // Thus we need to estimate 2 things:
    //	1) How many hashes were done if the work was aborted
    //	2) How high can the timeout be before the Icarus is idle,
    //		to minimise the number of work started
    //	We set 2) to 'the calculated estimate' - 1
    //	to ensure the estimate ends before idle
    //
    // The simple calculation used is:
    //	Tn = Total time in seconds to calculate n hashes
    //	Hs = seconds per hash
    //	Xn = number of hashes
    //	W  = code overhead per work
    //
    // Rough but reasonable estimate:
    //	Tn = Hs * Xn + W	(of the form y = mx + b)
    //
    // Thus:
    //	Line of best fit (using least squares)
    //
    //	Hs = (n*Sum(XiTi)-Sum(Xi)*Sum(Ti))/(n*Sum(Xi^2)-Sum(Xi)^2)
    //	W = Sum(Ti)/n - (Hs*Sum(Xi))/n
    //
    // N.B. W is less when aborting work since we aren't waiting for the reply
    //	to be transferred back (ICARUS_READ_TIME)
    //	Calculating the hashes aborted at n seconds is thus just n/Hs
    //	(though this is still a slight overestimate due to code delays)
    //
    
    // Both below must be exceeded to complete a set of data
    // Minimum how long after the first, the last data point must be
    #define HISTORY_SEC 60
    // Minimum how many points a single ICARUS_HISTORY should have
    #define MIN_DATA_COUNT 5
    // The value above used is doubled each history until it exceeds:
    #define MAX_MIN_DATA_COUNT 100
    
    static struct timeval history_sec = { HISTORY_SEC, 0 };
    
    // Store the last INFO_HISTORY data sets
    // [0] = current data, not yet ready to be included as an estimate
    // Each new data set throws the last old set off the end thus
    // keeping a ongoing average of recent data
    #define INFO_HISTORY 10
    
    struct ICARUS_HISTORY {
    	struct timeval finish;
    	double sumXiTi;
    	double sumXi;
    	double sumTi;
    	double sumXi2;
    	uint32_t values;
    	uint32_t hash_count_min;
    	uint32_t hash_count_max;
    };
    
    enum timing_mode { MODE_DEFAULT, MODE_SHORT, MODE_LONG, MODE_VALUE };
    
    static const char *MODE_DEFAULT_STR = "default";
    static const char *MODE_SHORT_STR = "short";
    static const char *MODE_LONG_STR = "long";
    static const char *MODE_VALUE_STR = "value";
    static const char *MODE_UNKNOWN_STR = "unknown";
    
    struct ICARUS_INFO {
    	// time to calculate the golden_ob
    	uint64_t golden_hashes;
    	struct timeval golden_tv;
    
    	struct ICARUS_HISTORY history[INFO_HISTORY+1];
    	uint32_t min_data_count;
    
    	// seconds per Hash
    	double Hs;
    	int read_count;
    
    	enum timing_mode timing_mode;
    	bool do_icarus_timing;
    
    	double fullnonce;
    	int count;
    	double W;
    	uint32_t values;
    	uint64_t hash_count_range;
    
    	// Determine the cost of history processing
    	// (which will only affect W)
    	uint64_t history_count;
    	struct timeval history_time;
    
    	// icarus-options
    	int baud;
    	int work_division;
    	int fpga_count;
    	uint32_t nonce_mask;
    };
    
    #define END_CONDITION 0x0000ffff
    
    // One for each possible device
    static struct ICARUS_INFO **icarus_info;
    
    // Looking for options in --icarus-timing and --icarus-options:
    //
    // Code increments this each time we start to look at a device
    // However, this means that if other devices are checked by
    // the Icarus code (e.g. BFL) they will count in the option offset
    //
    // This, however, is deterministic so that's OK
    //
    // If we were to increment after successfully finding an Icarus
    // that would be random since an Icarus may fail and thus we'd
    // not be able to predict the option order
    //
    // This also assumes that serial_detect() checks them sequentially
    // and in the order specified on the command line
    //
    static int option_offset = -1;
    
    struct device_api icarus_api;
    
    static void rev(unsigned char *s, size_t l)
    {
    	size_t i, j;
    	unsigned char t;
    
    	for (i = 0, j = l - 1; i < j; i++, j--) {
    		t = s[i];
    		s[i] = s[j];
    		s[j] = t;
    	}
    }
    
    #define icarus_open2(devpath, baud, purge)  serial_open(devpath, baud, ICARUS_READ_FAULT_DECISECONDS, purge)
    #define icarus_open(devpath, baud)  icarus_open2(devpath, baud, false)
    
    #define ICA_GETS_ERROR -1
    #define ICA_GETS_OK 0
    #define ICA_GETS_RESTART 1
    #define ICA_GETS_TIMEOUT 2
    
    static int icarus_gets(unsigned char *buf, int fd, struct timeval *tv_finish, struct thr_info *thr, int read_count)
    {
    	ssize_t ret = 0;
    	int rc = 0;
    	int read_amount = ICARUS_READ_SIZE;
    	bool first = true;
    
    	// Read reply 1 byte at a time to get earliest tv_finish
    	while (true) {
    		ret = read(fd, buf, 1);
    		if (ret < 0)
    			return ICA_GETS_ERROR;
    
    		if (first)
    			gettimeofday(tv_finish, NULL);
    
    		if (ret >= read_amount)
    			return ICA_GETS_OK;
    
    		if (ret > 0) {
    			buf += ret;
    			read_amount -= ret;
    			first = false;
    			continue;
    		}
    			
    		rc++;
    		if (rc >= read_count) {
    			if (opt_debug) {
    				applog(LOG_DEBUG,
    					"Icarus Read: No data in %.2f seconds",
    					(float)rc/(float)TIME_FACTOR);
    			}
    			return ICA_GETS_TIMEOUT;
    		}
    
    		if (thr && thr->work_restart) {
    			if (opt_debug) {
    				applog(LOG_DEBUG,
    					"Icarus Read: Work restart at %.2f seconds",
    					(float)(rc)/(float)TIME_FACTOR);
    			}
    			return ICA_GETS_RESTART;
    		}
    	}
    }
    
    static int icarus_write(int fd, const void *buf, size_t bufLen)
    {
    	size_t ret;
    
    	ret = write(fd, buf, bufLen);
    	if (unlikely(ret != bufLen))
    		return 1;
    
    	return 0;
    }
    
    #define icarus_close(fd) close(fd)
    
    static void do_icarus_close(struct thr_info *thr)
    {
    	struct cgpu_info *icarus = thr->cgpu;
    	icarus_close(icarus->device_fd);
    	icarus->device_fd = -1;
    }
    
    static const char *timing_mode_str(enum timing_mode timing_mode)
    {
    	switch(timing_mode) {
    	case MODE_DEFAULT:
    		return MODE_DEFAULT_STR;
    	case MODE_SHORT:
    		return MODE_SHORT_STR;
    	case MODE_LONG:
    		return MODE_LONG_STR;
    	case MODE_VALUE:
    		return MODE_VALUE_STR;
    	default:
    		return MODE_UNKNOWN_STR;
    	}
    }
    
    static void set_timing_mode(int this_option_offset, struct cgpu_info *icarus)
    {
    	struct ICARUS_INFO *info = icarus_info[icarus->device_id];
    	double Hs;
    	char buf[BUFSIZ+1];
    	char *ptr, *comma, *eq;
    	size_t max;
    	int i;
    
    	if (opt_icarus_timing == NULL)
    		buf[0] = '\0';
    	else {
    		ptr = opt_icarus_timing;
    		for (i = 0; i < this_option_offset; i++) {
    			comma = strchr(ptr, ',');
    			if (comma == NULL)
    				break;
    			ptr = comma + 1;
    		}
    
    		comma = strchr(ptr, ',');
    		if (comma == NULL)
    			max = strlen(ptr);
    		else
    			max = comma - ptr;
    
    		if (max > BUFSIZ)
    			max = BUFSIZ;
    		strncpy(buf, ptr, max);
    		buf[max] = '\0';
    	}
    
    	info->Hs = 0;
    	info->read_count = 0;
    
    	if (strcasecmp(buf, MODE_SHORT_STR) == 0) {
    		info->Hs = ICARUS_REV3_HASH_TIME;
    		info->read_count = ICARUS_READ_COUNT_TIMING;
    
    		info->timing_mode = MODE_SHORT;
    		info->do_icarus_timing = true;
    	} else if (strcasecmp(buf, MODE_LONG_STR) == 0) {
    		info->Hs = ICARUS_REV3_HASH_TIME;
    		info->read_count = ICARUS_READ_COUNT_TIMING;
    
    		info->timing_mode = MODE_LONG;
    		info->do_icarus_timing = true;
    	} else if ((Hs = atof(buf)) != 0) {
    		info->Hs = Hs / NANOSEC;
    		info->fullnonce = info->Hs * (((double)0xffffffff) + 1);
    
    		if ((eq = strchr(buf, '=')) != NULL)
    			info->read_count = atoi(eq+1);
    
    		if (info->read_count < 1)
    			info->read_count = (int)(info->fullnonce * TIME_FACTOR) - 1;
    
    		if (unlikely(info->read_count < 1))
    			info->read_count = 1;
    
    		info->timing_mode = MODE_VALUE;
    		info->do_icarus_timing = false;
    	} else {
    		// Anything else in buf just uses DEFAULT mode
    
    		info->Hs = ICARUS_REV3_HASH_TIME;
    		info->fullnonce = info->Hs * (((double)0xffffffff) + 1);
    
    		if ((eq = strchr(buf, '=')) != NULL)
    			info->read_count = atoi(eq+1);
    
    		if (info->read_count < 1)
    			info->read_count = (int)(info->fullnonce * TIME_FACTOR) - 1;
    
    		info->timing_mode = MODE_DEFAULT;
    		info->do_icarus_timing = false;
    	}
    
    	info->min_data_count = MIN_DATA_COUNT;
    
    	applog(LOG_DEBUG, "Icarus: Init: %d mode=%s read_count=%d Hs=%e",
    		icarus->device_id, timing_mode_str(info->timing_mode), info->read_count, info->Hs);
    }
    
    static uint32_t mask(int work_division)
    {
    	char err_buf[BUFSIZ+1];
    	uint32_t nonce_mask = 0x7fffffff;
    
    	// yes we can calculate these, but this way it's easy to see what they are
    	switch (work_division) {
    	case 1:
    		nonce_mask = 0xffffffff;
    		break;
    	case 2:
    		nonce_mask = 0x7fffffff;
    		break;
    	case 4:
    		nonce_mask = 0x3fffffff;
    		break;
    	case 8:
    		nonce_mask = 0x1fffffff;
    		break;
    	default:
    		sprintf(err_buf, "Invalid2 icarus-options for work_division (%d) must be 1, 2, 4 or 8", work_division);
    		quit(1, err_buf);
    	}
    
    	return nonce_mask;
    }
    
    static void get_options(int this_option_offset, int *baud, int *work_division, int *fpga_count)
    {
    	char err_buf[BUFSIZ+1];
    	char buf[BUFSIZ+1];
    	char *ptr, *comma, *colon, *colon2;
    	size_t max;
    	int i, tmp;
    
    	if (opt_icarus_options == NULL)
    		buf[0] = '\0';
    	else {
    		ptr = opt_icarus_options;
    		for (i = 0; i < this_option_offset; i++) {
    			comma = strchr(ptr, ',');
    			if (comma == NULL)
    				break;
    			ptr = comma + 1;
    		}
    
    		comma = strchr(ptr, ',');
    		if (comma == NULL)
    			max = strlen(ptr);
    		else
    			max = comma - ptr;
    
    		if (max > BUFSIZ)
    			max = BUFSIZ;
    		strncpy(buf, ptr, max);
    		buf[max] = '\0';
    	}
    
    	*baud = ICARUS_IO_SPEED;
    	*work_division = 2;
    	*fpga_count = 2;
    
    	if (*buf) {
    		colon = strchr(buf, ':');
    		if (colon)
    			*(colon++) = '\0';
    
    		if (*buf) {
    			tmp = atoi(buf);
    			switch (tmp) {
    			case 115200:
    				*baud = 115200;
    				break;
    			case 57600:
    				*baud = 57600;
    				break;
    			default:
    				sprintf(err_buf, "Invalid icarus-options for baud (%s) must be 115200 or 57600", buf);
    				quit(1, err_buf);
    			}
    		}
    
    		if (colon && *colon) {
    			colon2 = strchr(colon, ':');
    			if (colon2)
    				*(colon2++) = '\0';
    
    			if (*colon) {
    				tmp = atoi(colon);
    				if (tmp == 1 || tmp == 2 || tmp == 4 || tmp == 8) {
    					*work_division = tmp;
    					*fpga_count = tmp;	// default to the same
    				} else {
    					sprintf(err_buf, "Invalid icarus-options for work_division (%s) must be 1, 2, 4 or 8", colon);
    					quit(1, err_buf);
    				}
    			}
    
    			if (colon2 && *colon2) {
    				tmp = atoi(colon2);
    				if (tmp > 0 && tmp <= *work_division)
    					*fpga_count = tmp;
    				else {
    					sprintf(err_buf, "Invalid icarus-options for fpga_count (%s) must be >0 and <=work_division (%d)", colon2, *work_division);
    					quit(1, err_buf);
    				}
    			}
    		}
    	}
    }
    
    static bool icarus_detect_one(const char *devpath)
    {
    	int this_option_offset = ++option_offset;
    
    	struct ICARUS_INFO *info;
    	struct timeval tv_start, tv_finish;
    	int fd;
    
    	// Block 171874 nonce = (0xa2870100) = 0x000187a2
    	// N.B. golden_ob MUST take less time to calculate
    	//	than the timeout set in icarus_open()
    	//	This one takes ~0.53ms on Rev3 Icarus
    	const char golden_ob[] =
    		"4679ba4ec99876bf4bfe086082b40025"
    		"4df6c356451471139a3afa71e48f544a"
    		"00000000000000000000000000000000"
    		"0000000087320b1a1426674f2fa722ce";
    
    	const char golden_nonce[] = "000187a2";
    	const uint32_t golden_nonce_val = 0x000187a2;
    
    	unsigned char ob_bin[64], nonce_bin[ICARUS_READ_SIZE];
    	char *nonce_hex;
    
    	int baud, work_division, fpga_count;
    
    	get_options(this_option_offset, &baud, &work_division, &fpga_count);
    
    	applog(LOG_DEBUG, "Icarus Detect: Attempting to open %s", devpath);
    
    	fd = icarus_open2(devpath, baud, true);
    	if (unlikely(fd == -1)) {
    		applog(LOG_ERR, "Icarus Detect: Failed to open %s", devpath);
    		return false;
    	}
    
    	hex2bin(ob_bin, golden_ob, sizeof(ob_bin));
    	icarus_write(fd, ob_bin, sizeof(ob_bin));
    	gettimeofday(&tv_start, NULL);
    
    	memset(nonce_bin, 0, sizeof(nonce_bin));
    	icarus_gets(nonce_bin, fd, &tv_finish, NULL, 1);
    
    	icarus_close(fd);
    
    	nonce_hex = bin2hex(nonce_bin, sizeof(nonce_bin));
    	if (strncmp(nonce_hex, golden_nonce, 8)) {
    		applog(LOG_ERR,
    			"Icarus Detect: "
    			"Test failed at %s: get %s, should: %s",
    			devpath, nonce_hex, golden_nonce);
    		free(nonce_hex);
    		return false;
    	}
    	applog(LOG_DEBUG,
    		"Icarus Detect: "
    		"Test succeeded at %s: got %s",
    			devpath, nonce_hex);
    	free(nonce_hex);
    
    	/* We have a real Icarus! */
    	struct cgpu_info *icarus;
    	icarus = calloc(1, sizeof(struct cgpu_info));
    	icarus->api = &icarus_api;
    	icarus->device_path = strdup(devpath);
    	icarus->device_fd = -1;
    	icarus->threads = 1;
    	add_cgpu(icarus);
    	icarus_info = realloc(icarus_info, sizeof(struct ICARUS_INFO *) * (total_devices + 1));
    
    	applog(LOG_INFO, "Found Icarus at %s, mark as %d",
    		devpath, icarus->device_id);
    
    	applog(LOG_DEBUG, "Icarus: Init: %d baud=%d work_division=%d fpga_count=%d",
    		icarus->device_id, baud, work_division, fpga_count);
    
    	// Since we are adding a new device on the end it needs to always be allocated
    	icarus_info[icarus->device_id] = (struct ICARUS_INFO *)malloc(sizeof(struct ICARUS_INFO));
    	if (unlikely(!(icarus_info[icarus->device_id])))
    		quit(1, "Failed to malloc ICARUS_INFO");
    
    	info = icarus_info[icarus->device_id];
    
    	// Initialise everything to zero for a new device
    	memset(info, 0, sizeof(struct ICARUS_INFO));
    
    	info->baud = baud;
    	info->work_division = work_division;
    	info->fpga_count = fpga_count;
    	info->nonce_mask = mask(work_division);
    
    	info->golden_hashes = (golden_nonce_val & info->nonce_mask) * fpga_count;
    	timersub(&tv_finish, &tv_start, &(info->golden_tv));
    
    	set_timing_mode(this_option_offset, icarus);
    
    	return true;
    }
    
    static void icarus_detect()
    {
    	serial_detect(&icarus_api, icarus_detect_one);
    }
    
    static bool icarus_prepare(struct thr_info *thr)
    {
    	struct cgpu_info *icarus = thr->cgpu;
    
    	struct timeval now;
    
    	icarus->device_fd = -1;
    
    	int fd = icarus_open(icarus->device_path, icarus_info[icarus->device_id]->baud);
    	if (unlikely(-1 == fd)) {
    		applog(LOG_ERR, "Failed to open Icarus on %s",
    		       icarus->device_path);
    		return false;
    	}
    
    	icarus->device_fd = fd;
    
    	applog(LOG_INFO, "Opened Icarus on %s", icarus->device_path);
    	gettimeofday(&now, NULL);
    	get_datestamp(icarus->init, &now);
    
    	return true;
    }
    
    static int64_t icarus_scanhash(struct thr_info *thr, struct work *work,
    				__maybe_unused int64_t max_nonce)
    {
    	struct cgpu_info *icarus;
    	int fd;
    	int ret;
    
    	struct ICARUS_INFO *info;
    
    	unsigned char ob_bin[64], nonce_bin[ICARUS_READ_SIZE];
    	char *ob_hex;
    	uint32_t nonce;
    	int64_t hash_count;
    	struct timeval tv_start, tv_finish, elapsed;
    	struct timeval tv_history_start, tv_history_finish;
    	double Ti, Xi;
    	int curr_hw_errors, i;
    	bool was_hw_error;
    
    	struct ICARUS_HISTORY *history0, *history;
    	int count;
    	double Hs, W, fullnonce;
    	int read_count;
    	int64_t estimate_hashes;
    	uint32_t values;
    	int64_t hash_count_range;
    
    	elapsed.tv_sec = elapsed.tv_usec = 0;
    
    	icarus = thr->cgpu;
    	if (icarus->device_fd == -1)
    		if (!icarus_prepare(thr)) {
    			applog(LOG_ERR, "ICA%i: Comms error", icarus->device_id);
    			dev_error(icarus, REASON_DEV_COMMS_ERROR);
    
    			// fail the device if the reopen attempt fails
    			return -1;
    		}
    
    	fd = icarus->device_fd;
    
    	memset(ob_bin, 0, sizeof(ob_bin));
    	memcpy(ob_bin, work->midstate, 32);
    	memcpy(ob_bin + 52, work->data + 64, 12);
    	rev(ob_bin, 32);
    	rev(ob_bin + 52, 12);
    #ifndef WIN32
    	tcflush(fd, TCOFLUSH);
    #endif
    	ret = icarus_write(fd, ob_bin, sizeof(ob_bin));
    	if (ret) {
    		do_icarus_close(thr);
    		applog(LOG_ERR, "ICA%i: Comms error", icarus->device_id);
    		dev_error(icarus, REASON_DEV_COMMS_ERROR);
    		return 0;	/* This should never happen */
    	}
    
    	gettimeofday(&tv_start, NULL);
    
    	if (opt_debug) {
    		ob_hex = bin2hex(ob_bin, sizeof(ob_bin));
    		applog(LOG_DEBUG, "Icarus %d sent: %s",
    			icarus->device_id, ob_hex);
    		free(ob_hex);
    	}
    
    	/* Icarus will return 4 bytes (ICARUS_READ_SIZE) nonces or nothing */
    	memset(nonce_bin, 0, sizeof(nonce_bin));
    	info = icarus_info[icarus->device_id];
    	ret = icarus_gets(nonce_bin, fd, &tv_finish, thr, info->read_count);
    	if (ret == ICA_GETS_ERROR) {
    		do_icarus_close(thr);
    		applog(LOG_ERR, "ICA%i: Comms error", icarus->device_id);
    		dev_error(icarus, REASON_DEV_COMMS_ERROR);
    		return 0;
    	}
    
    	work->blk.nonce = 0xffffffff;
    
    	// aborted before becoming idle, get new work
    	if (ret == ICA_GETS_TIMEOUT || ret == ICA_GETS_RESTART) {
    		timersub(&tv_finish, &tv_start, &elapsed);
    
    		// ONLY up to just when it aborted
    		// We didn't read a reply so we don't subtract ICARUS_READ_TIME
    		estimate_hashes = ((double)(elapsed.tv_sec)
    					+ ((double)(elapsed.tv_usec))/((double)1000000)) / info->Hs;
    
    		// If some Serial-USB delay allowed the full nonce range to
    		// complete it can't have done more than a full nonce
    		if (unlikely(estimate_hashes > 0xffffffff))
    			estimate_hashes = 0xffffffff;
    
    		if (opt_debug) {
    			applog(LOG_DEBUG, "Icarus %d no nonce = 0x%08llx hashes (%ld.%06lds)",
    					icarus->device_id, estimate_hashes,
    					elapsed.tv_sec, elapsed.tv_usec);
    		}
    
    		return estimate_hashes;
    	}
    
    	memcpy((char *)&nonce, nonce_bin, sizeof(nonce_bin));
    
    #if !defined (__BIG_ENDIAN__) && !defined(MIPSEB)
    	nonce = swab32(nonce);
    #endif
    
    	curr_hw_errors = icarus->hw_errors;
    	submit_nonce(thr, work, nonce);
    	was_hw_error = (curr_hw_errors > icarus->hw_errors);
    
    	// Force a USB close/reopen on any hw error
    	if (was_hw_error)
    		do_icarus_close(thr);
    
    	hash_count = (nonce & info->nonce_mask);
    	hash_count++;
    	hash_count *= info->fpga_count;
    
    	if (opt_debug || info->do_icarus_timing)
    		timersub(&tv_finish, &tv_start, &elapsed);
    
    	if (opt_debug) {
    		applog(LOG_DEBUG, "Icarus %d nonce = 0x%08x = 0x%08llx hashes (%ld.%06lds)",
    				icarus->device_id, nonce, hash_count, elapsed.tv_sec, elapsed.tv_usec);
    	}
    
    	// ignore possible end condition values ... and hw errors
    	if (info->do_icarus_timing
    	&&  !was_hw_error
    	&&  ((nonce & info->nonce_mask) > END_CONDITION)
    	&&  ((nonce & info->nonce_mask) < (info->nonce_mask & ~END_CONDITION))) {
    		gettimeofday(&tv_history_start, NULL);
    
    		history0 = &(info->history[0]);
    
    		if (history0->values == 0)
    			timeradd(&tv_start, &history_sec, &(history0->finish));
    
    		Ti = (double)(elapsed.tv_sec)
    			+ ((double)(elapsed.tv_usec))/((double)1000000)
    			- ((double)ICARUS_READ_TIME(info->baud));
    		Xi = (double)hash_count;
    		history0->sumXiTi += Xi * Ti;
    		history0->sumXi += Xi;
    		history0->sumTi += Ti;
    		history0->sumXi2 += Xi * Xi;
    
    		history0->values++;
    
    		if (history0->hash_count_max < hash_count)
    			history0->hash_count_max = hash_count;
    		if (history0->hash_count_min > hash_count || history0->hash_count_min == 0)
    			history0->hash_count_min = hash_count;
    
    		if (history0->values >= info->min_data_count
    		&&  timercmp(&tv_start, &(history0->finish), >)) {
    			for (i = INFO_HISTORY; i > 0; i--)
    				memcpy(&(info->history[i]),
    					&(info->history[i-1]),
    					sizeof(struct ICARUS_HISTORY));
    
    			// Initialise history0 to zero for summary calculation
    			memset(history0, 0, sizeof(struct ICARUS_HISTORY));
    
    			// We just completed a history data set
    			// So now recalc read_count based on the whole history thus we will
    			// initially get more accurate until it completes INFO_HISTORY
    			// total data sets
    			count = 0;
    			for (i = 1 ; i <= INFO_HISTORY; i++) {
    				history = &(info->history[i]);
    				if (history->values >= MIN_DATA_COUNT) {
    					count++;
    
    					history0->sumXiTi += history->sumXiTi;
    					history0->sumXi += history->sumXi;
    					history0->sumTi += history->sumTi;
    					history0->sumXi2 += history->sumXi2;
    					history0->values += history->values;
    
    					if (history0->hash_count_max < history->hash_count_max)
    						history0->hash_count_max = history->hash_count_max;
    					if (history0->hash_count_min > history->hash_count_min || history0->hash_count_min == 0)
    						history0->hash_count_min = history->hash_count_min;
    				}
    			}
    
    			// All history data
    			Hs = (history0->values*history0->sumXiTi - history0->sumXi*history0->sumTi)
    				/ (history0->values*history0->sumXi2 - history0->sumXi*history0->sumXi);
    			W = history0->sumTi/history0->values - Hs*history0->sumXi/history0->values;
    			hash_count_range = history0->hash_count_max - history0->hash_count_min;
    			values = history0->values;
    			
    			// Initialise history0 to zero for next data set
    			memset(history0, 0, sizeof(struct ICARUS_HISTORY));
    
    			fullnonce = W + Hs * (((double)0xffffffff) + 1);
    			read_count = (int)(fullnonce * TIME_FACTOR) - 1;
    
    			info->Hs = Hs;
    			info->read_count = read_count;
    
    			info->fullnonce = fullnonce;
    			info->count = count;
    			info->W = W;
    			info->values = values;
    			info->hash_count_range = hash_count_range;
    
    			if (info->min_data_count < MAX_MIN_DATA_COUNT)
    				info->min_data_count *= 2;
    			else if (info->timing_mode == MODE_SHORT)
    				info->do_icarus_timing = false;
    
    //			applog(LOG_WARNING, "Icarus %d Re-estimate: read_count=%d fullnonce=%fs history count=%d Hs=%e W=%e values=%d hash range=0x%08lx min data count=%u", icarus->device_id, read_count, fullnonce, count, Hs, W, values, hash_count_range, info->min_data_count);
    			applog(LOG_WARNING, "Icarus %d Re-estimate: Hs=%e W=%e read_count=%d fullnonce=%.3fs",
    					icarus->device_id, Hs, W, read_count, fullnonce);
    		}
    		info->history_count++;
    		gettimeofday(&tv_history_finish, NULL);
    
    		timersub(&tv_history_finish, &tv_history_start, &tv_history_finish);
    		timeradd(&tv_history_finish, &(info->history_time), &(info->history_time));
    	}
    
    	return hash_count;
    }
    
    static struct api_data *icarus_api_stats(struct cgpu_info *cgpu)
    {
    	struct api_data *root = NULL;
    	struct ICARUS_INFO *info = icarus_info[cgpu->device_id];
    
    	// 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_int(root, "read_count", &(info->read_count), false);
    	root = api_add_double(root, "fullnonce", &(info->fullnonce), false);
    	root = api_add_int(root, "count", &(info->count), false);
    	root = api_add_hs(root, "Hs", &(info->Hs), false);
    	root = api_add_double(root, "W", &(info->W), false);
    	root = api_add_uint(root, "total_values", &(info->values), false);
    	root = api_add_uint64(root, "range", &(info->hash_count_range), false);
    	root = api_add_uint64(root, "history_count", &(info->history_count), false);
    	root = api_add_timeval(root, "history_time", &(info->history_time), false);
    	root = api_add_uint(root, "min_data_count", &(info->min_data_count), false);
    	root = api_add_uint(root, "timing_values", &(info->history[0].values), false);
    	root = api_add_const(root, "timing_mode", timing_mode_str(info->timing_mode), false);
    	root = api_add_bool(root, "is_timing", &(info->do_icarus_timing), false);
    	root = api_add_int(root, "baud", &(info->baud), false);
    	root = api_add_int(root, "work_division", &(info->work_division), false);
    	root = api_add_int(root, "fpga_count", &(info->fpga_count), false);
    
    	return root;
    }
    
    static void icarus_shutdown(struct thr_info *thr)
    {
    	do_icarus_close(thr);
    }
    
    struct device_api icarus_api = {
    	.dname = "icarus",
    	.name = "ICA",
    	.api_detect = icarus_detect,
    	.get_api_stats = icarus_api_stats,
    	.thread_prepare = icarus_prepare,
    	.scanhash = icarus_scanhash,
    	.thread_shutdown = icarus_shutdown,
    };