USB automatically handle losing the device and report nodev in the API

API-README

@@ -419,6 +419,7 @@ Added API commands:
 
 Modified API commands:
  'pools' - add 'Best Share'
+ 'devs' and 'pga' - add 'No Device' for PGAs if MMQ or BFL compiled
 
 ----------
 

api.c

@@ -391,6 +391,7 @@ static const char *JSON_PARAMETER = "parameter";
 #define MSG_ZERINV 95
 #define MSG_ZERSUM 96
 #define MSG_ZERNOSUM 97
+#define MSG_USBNODEV 98
 
 enum code_severity {
 	SEVERITY_ERR,
@@ -568,6 +569,9 @@ struct CODES {
  { SEVERITY_ERR,   MSG_ZERINV,	PARAM_STR,	"Invalid zero parameter '%s'" },
  { SEVERITY_SUCC,  MSG_ZERSUM,	PARAM_STR,	"Zeroed %s stats with summary" },
  { SEVERITY_SUCC,  MSG_ZERNOSUM, PARAM_STR,	"Zeroed %s stats without summary" },
+#if defined(USE_MODMINER) || defined(USE_BITFORCE)
+ { SEVERITY_ERR,   MSG_USBNODEV, PARAM_PGA,	"PGA%d has no device" },
+#endif
  { SEVERITY_FAIL, 0, 0, NULL }
 };
 
@@ -1570,6 +1574,9 @@ static void pgastatus(struct io_data *io_data, int pga, bool isjson, bool precom
 		root = api_add_diff(root, "Difficulty Accepted", &(cgpu->diff_accepted), false);
 		root = api_add_diff(root, "Difficulty Rejected", &(cgpu->diff_rejected), false);
 		root = api_add_diff(root, "Last Share Difficulty", &(cgpu->last_share_diff), false);
+#if defined(USE_MODMINER) || defined(USE_BITFORCE)
+		root = api_add_bool(root, "No Device", &(cgpu->nodev), false);
+#endif
 
 		root = print_data(root, buf, isjson, precom);
 		io_add(io_data, buf);
@@ -1785,6 +1792,13 @@ static void pgaenable(struct io_data *io_data, __maybe_unused SOCKETTYPE c, char
 	}
 #endif
 
+#if defined(USE_MODMINER) || defined(USE_BITFORCE)
+	if (cgpu->nodev) {
+		message(io_data, MSG_USBNODEV, id, NULL, isjson);
+		return;
+	}
+#endif
+
 	for (i = 0; i < mining_threads; i++) {
 		pga = thr_info[i].cgpu->cgminer_id;
 		if (pga == dev) {

driver-bitforce.c

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012 Andrew Smith
+ * Copyright 2012-2013 Andrew Smith
  * Copyright 2012 Luke Dashjr
  * Copyright 2012 Con Kolivas
  *
@@ -82,13 +82,19 @@ static void bitforce_initialise(struct cgpu_info *bitforce, bool lock)
 		applog(LOG_DEBUG, "%s%i: reset got err %d",
 			bitforce->drv->name, bitforce->device_id, err);
 
+	if (bitforce->nodev)
+		goto failed;
+
 	// Set data control
 	err = usb_transfer(bitforce, FTDI_TYPE_OUT, FTDI_REQUEST_DATA,
 				FTDI_VALUE_DATA, bitforce->usbdev->found->interface, C_SETDATA);
 	if (opt_debug)
 		applog(LOG_DEBUG, "%s%i: setdata got err %d",
 			bitforce->drv->name, bitforce->device_id, err);
 
+	if (bitforce->nodev)
+		goto failed;
+
 	// Set the baud
 	err = usb_transfer(bitforce, FTDI_TYPE_OUT, FTDI_REQUEST_BAUD, FTDI_VALUE_BAUD,
 				(FTDI_INDEX_BAUD & 0xff00) | bitforce->usbdev->found->interface,
@@ -97,34 +103,48 @@ static void bitforce_initialise(struct cgpu_info *bitforce, bool lock)
 		applog(LOG_DEBUG, "%s%i: setbaud got err %d",
 			bitforce->drv->name, bitforce->device_id, err);
 
+	if (bitforce->nodev)
+		goto failed;
+
 	// Set Flow Control
 	err = usb_transfer(bitforce, FTDI_TYPE_OUT, FTDI_REQUEST_FLOW,
 				FTDI_VALUE_FLOW, bitforce->usbdev->found->interface, C_SETFLOW);
 	if (opt_debug)
 		applog(LOG_DEBUG, "%s%i: setflowctrl got err %d",
 			bitforce->drv->name, bitforce->device_id, err);
 
+	if (bitforce->nodev)
+		goto failed;
+
 	// Set Modem Control
 	err = usb_transfer(bitforce, FTDI_TYPE_OUT, FTDI_REQUEST_MODEM,
 				FTDI_VALUE_MODEM, bitforce->usbdev->found->interface, C_SETMODEM);
 	if (opt_debug)
 		applog(LOG_DEBUG, "%s%i: setmodemctrl got err %d",
 			bitforce->drv->name, bitforce->device_id, err);
 
+	if (bitforce->nodev)
+		goto failed;
+
 	// Clear any sent data
 	err = usb_transfer(bitforce, FTDI_TYPE_OUT, FTDI_REQUEST_RESET,
 				FTDI_VALUE_PURGE_TX, bitforce->usbdev->found->interface, C_PURGETX);
 	if (opt_debug)
 		applog(LOG_DEBUG, "%s%i: purgetx got err %d",
 			bitforce->drv->name, bitforce->device_id, err);
 
+	if (bitforce->nodev)
+		goto failed;
+
 	// Clear any received data
 	err = usb_transfer(bitforce, FTDI_TYPE_OUT, FTDI_REQUEST_RESET,
 				FTDI_VALUE_PURGE_RX, bitforce->usbdev->found->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);
 }
@@ -322,6 +342,10 @@ static bool bitforce_get_temp(struct cgpu_info *bitforce)
 	int err, amount;
 	char *s;
 
+	// Device is gone
+	if (bitforce->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)
@@ -640,6 +664,10 @@ static int64_t bitforce_scanhash(struct thr_info *thr, struct work *work, int64_
 	bool send_ret;
 	int64_t ret;
 
+	// Device is gone
+	if (bitforce->nodev)
+		return -1;
+
 	send_ret = bitforce_send_work(thr, work);
 
 	if (!restart_wait(bitforce->sleep_ms))

driver-modminer.c

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012 Andrew Smith
+ * Copyright 2012-2013 Andrew Smith
  * Copyright 2012 Luke Dashjr
  *
  * This program is free software; you can redistribute it and/or modify it
@@ -607,6 +607,7 @@ static bool modminer_fpga_prepare(struct thr_info *thr)
  *
  * N.B. clock must always be a multiple of 2
  */
+static const char *clocknodev = "clock failed - no device";
 static const char *clockoldwork = "clock already changed for this work";
 static const char *clocktoolow = "clock too low";
 static const char *clocktoohi = "clock too high";
@@ -620,6 +621,10 @@ static const char *modminer_delta_clock(struct thr_info *thr, int delta, bool te
 	unsigned char cmd[6], buf[1];
 	int err, amount;
 
+	// Device is gone
+	if (modminer->nodev)
+		return clocknodev;
+
 	// Only do once if multiple shares per work or multiple reasons
 	if (!state->new_work && !force)
 		return clockoldwork;
@@ -775,9 +780,6 @@ static bool modminer_start_work(struct thr_info *thr)
 	mutex_lock(modminer->modminer_mutex);
 
 	if ((err = usb_write(modminer, (char *)(state->next_work_cmd), 46, &amount, C_SENDWORK)) < 0 || amount != 46) {
-// TODO: err = LIBUSB_ERROR_NO_DEVICE means the MMQ disappeared
-// - need to delete it and rescan for it? (after a delay?)
-// but check all (4) disappeared
 		mutex_unlock(modminer->modminer_mutex);
 
 		applog(LOG_ERR, "%s%u: Start work failed (%d:%d)",
@@ -807,6 +809,10 @@ static void check_temperature(struct thr_info *thr)
 	int tbytes, tamount;
 	int amount;
 
+	// Device is gone
+	if (modminer->nodev)
+		return;
+
 	if (state->one_byte_temp) {
 		cmd[0] = MODMINER_TEMP1;
 		tbytes = 1;
@@ -891,6 +897,10 @@ static uint64_t modminer_process_results(struct thr_info *thr)
 	double timeout;
 	int temploop;
 
+	// Device is gone
+	if (modminer->nodev)
+		return -1;
+
 	// If we are overheated it will just keep checking for results
 	// since we can't stop the work
 	// The next work will not start until the temp drops
@@ -904,9 +914,6 @@ static uint64_t modminer_process_results(struct thr_info *thr)
 	while (1) {
 		mutex_lock(modminer->modminer_mutex);
 		if ((err = usb_write(modminer, cmd, 2, &amount, C_REQUESTWORKSTATUS)) < 0 || amount != 2) {
-// TODO: err = LIBUSB_ERROR_NO_DEVICE means the MMQ disappeared
-// - need to delete it and rescan for it? (after a delay?)
-// but check all (4) disappeared
 			mutex_unlock(modminer->modminer_mutex);
 
 			// timeoutloop never resets so the timeouts can't
@@ -1053,6 +1060,10 @@ static int64_t modminer_scanhash(struct thr_info *thr, struct work *work, int64_
 	bool startwork;
 	struct timeval tv1, tv2;
 
+	// Device is gone
+	if (thr->cgpu->nodev)
+		return -1;
+
 	// Don't start new work if overheated
 	if (state->overheated == true) {
 		gettimeofday(&tv1, NULL);
@@ -1062,6 +1073,10 @@ static int64_t modminer_scanhash(struct thr_info *thr, struct work *work, int64_
 		while (state->overheated == true) {
 			check_temperature(thr);
 
+			// Device is gone
+			if (thr->cgpu->nodev)
+				return -1;
+
 			if (state->overheated == true) {
 				gettimeofday(&tv2, NULL);
 

miner.h

@@ -399,6 +399,7 @@ struct cgpu_info {
 	};
 #if defined(USE_MODMINER) || defined(USE_BITFORCE)
 	int usbstat;
+	bool nodev;
 #endif
 #ifdef USE_MODMINER
 	char fpgaid;