Make bitforce nonce range support a command line option --bfl-range since enabling it decrease hashrate by 1%.

cgminer.c

@@ -144,6 +144,9 @@ char *opt_icarus_timing = NULL;
 char *opt_kernel_path;
 char *cgminer_path;
 
+#if defined(USE_BITFORCE)
+bool opt_bfl_noncerange;
+#endif
 #define QUIET	(opt_quiet || opt_realquiet)
 
 struct thr_info *thr_info;
@@ -776,6 +779,11 @@ static struct opt_table opt_config_table[] = {
 	OPT_WITHOUT_ARG("--benchmark",
 			opt_set_bool, &opt_benchmark,
 			"Run cgminer in benchmark mode - produces no shares"),
+#if defined(USE_BITFORCE)
+	OPT_WITHOUT_ARG("--bfl-range",
+			opt_set_bool, &opt_bfl_noncerange,
+			"Use nonce range on bitforce devices if supported"),
+#endif
 #ifdef WANT_CPUMINE
 	OPT_WITH_ARG("--bench-algo|-b",
 		     set_int_0_to_9999, opt_show_intval, &opt_bench_algo,

driver-bitforce.c

@@ -83,10 +83,13 @@ static bool bitforce_detect_one(const char *devpath)
 	bitforce->device_path = strdup(devpath);
 	bitforce->deven = DEV_ENABLED;
 	bitforce->threads = 1;
-	bitforce->sleep_ms = BITFORCE_SLEEP_MS;
 	/* Initially enable support for nonce range and disable it later if it
 	 * fails */
-	bitforce->nonce_range = true;
+	if (opt_bfl_noncerange) {
+		bitforce->nonce_range = true;
+		bitforce->sleep_ms = BITFORCE_SLEEP_MS;
+	} else
+		bitforce->sleep_ms = BITFORCE_SLEEP_MS * 5;
 
 	if (likely((!memcmp(pdevbuf, ">>>ID: ", 7)) && (s = strstr(pdevbuf + 3, ">>>")))) {
 		s[0] = '\0';

miner.h

@@ -545,6 +545,9 @@ extern bool opt_api_network;
 extern bool opt_delaynet;
 extern bool opt_restart;
 extern char *opt_icarus_timing;
+#ifdef USE_BITFORCE
+extern bool opt_bfl_noncerange;
+#endif
 
 extern pthread_rwlock_t netacc_lock;