thodg/cgminer

diff --git a/driver-hashfast.c b/driver-hashfast.c
index a26c518..0f7a210 100644
--- a/driver-hashfast.c
+++ b/driver-hashfast.c
@@ -411,12 +411,11 @@ struct hf_settings_data {
 
 static bool hfa_set_voltages(struct cgpu_info *hashfast, struct hashfast_info *info)
 {
-	uint16_t magic = 0x42AA;
 	struct hf_settings_data op_settings_data;
 
 	op_settings_data.revision = 1;
 	op_settings_data.ref_frequency = 25;
-	op_settings_data.magic = magic;
+	op_settings_data.magic = HFA_MAGIC_SETTINGS_VALUE;
 
 	op_settings_data.frequency0 = info->hash_clock_rate;
 	op_settings_data.voltage0 = info->hash_voltage;
@@ -427,7 +426,8 @@ static bool hfa_set_voltages(struct cgpu_info *hashfast, struct hashfast_info *i
 	op_settings_data.frequency3 = info->hash_clock_rate;
 	op_settings_data.voltage3 = info->hash_voltage;
 
-	hfa_send_generic_frame(hashfast, OP_SETTINGS, 0x00, 0x01, magic, (uint8_t *)&op_settings_data, sizeof(op_settings_data));
+	hfa_send_generic_frame(hashfast, OP_SETTINGS, 0x00, 0x01, HFA_MAGIC_SETTINGS_VALUE,
+		(uint8_t *)&op_settings_data, sizeof(op_settings_data));
 	// reset the board once to switch to new voltage settings
 	hfa_send_generic_frame(hashfast, OP_POWER, 0xff, 0x00, 0x1, NULL, 0);
 	hfa_send_generic_frame(hashfast, OP_POWER, 0xff, 0x00, 0x2, NULL, 0);
@@ -762,7 +762,6 @@ static void hfa_check_options(struct hashfast_info *info)
 						break;
 					}
 					info->hash_voltage = lval;
-					info->set_voltage_needed = true;
 				}
 				break;
 		}
@@ -1256,6 +1255,35 @@ static void hfa_parse_notice(struct cgpu_info *hashfast, struct hf_header *h)
 	applog(LOG_NOTICE, "%s %s NOTICE: %s", hashfast->drv->name, hashfast->unique_id, d->message);
 }
 
+static void hfa_parse_settings(struct cgpu_info *hashfast, struct hf_header *h)
+{
+	struct hashfast_info *info = hashfast->device_data;
+	struct hf_settings_data *op_settings_data = (struct hf_settings_data *)(h + 1);
+
+	// Check if packet size, revision and magic are matching
+	if ((h->data_length * 4 == sizeof(struct hf_settings_data)) &&
+	    (h->core_address == 0) &&
+	    (op_settings_data->revision == 1) &&
+	    (op_settings_data->magic == HFA_MAGIC_SETTINGS_VALUE))
+	{
+		applog(LOG_NOTICE, "%s: Device settings (%dMHz@%dmV,%dMHz@%dmV,%dMHz@%dmV,%dMHz@%dmV)", hashfast->drv->name,
+			op_settings_data->frequency0, op_settings_data->voltage0,
+			op_settings_data->frequency1, op_settings_data->voltage1,
+			op_settings_data->frequency2, op_settings_data->voltage2,
+			op_settings_data->frequency3, op_settings_data->voltage3);
+		// Set voltage only when current voltage values are different
+		if ((info->hash_voltage != 0) &&
+		    ((op_settings_data->voltage0 != info->hash_voltage) ||
+		     (op_settings_data->voltage1 != info->hash_voltage) ||
+		     (op_settings_data->voltage2 != info->hash_voltage) ||
+		     (op_settings_data->voltage3 != info->hash_voltage))) {
+			applog(LOG_NOTICE, "%s: Setting default clock and voltage to %dMHz@%dmV",
+				hashfast->drv->name, info->hash_clock_rate, info->hash_voltage);
+			hfa_set_voltages(hashfast, info);
+		}
+	}
+}
+
 static void *hfa_read(void *arg)
 {
 	struct thr_info *thr = (struct thr_info *)arg;
@@ -1300,6 +1328,9 @@ static void *hfa_read(void *arg)
 			case OP_USB_NOTICE:
 				hfa_parse_notice(hashfast, h);
 				break;
+			case OP_SETTINGS:
+				hfa_parse_settings(hashfast, h);
+				break;
 			case OP_POWER:
 			case OP_PING:
 				/* Do nothing */
@@ -1397,12 +1428,8 @@ static bool hfa_init(struct thr_info *thr)
 		}
 	}
 
-	if (info->set_voltage_needed) {
-		applog(LOG_NOTICE, "%s: Set default clock and voltage to %dMHz@%dmV",
-			hashfast->drv->name, info->hash_clock_rate, info->hash_voltage);
-		hfa_set_voltages(hashfast, info);
-		info->set_voltage_needed = false;
-	}
+	// Read current device settings
+	hfa_send_generic_frame(hashfast, OP_SETTINGS, 0x00, 0x00, HFA_MAGIC_SETTINGS_VALUE, NULL, 0);
 
 	mutex_init(&info->lock);
 	mutex_init(&info->rlock);
diff --git a/driver-hashfast.h b/driver-hashfast.h
index 28cda1a..331bbd6 100644
--- a/driver-hashfast.h
+++ b/driver-hashfast.h
@@ -45,6 +45,7 @@ char *opt_hfa_options;
 #define HFA_FAN_MIN 5
 #define HFA_VOLTAGE_MAX 1000
 #define HFA_VOLTAGE_MIN 500
+#define HFA_MAGIC_SETTINGS_VALUE 0x42AA
 
 // # Factory Operation Codes
 #define OP_SETTINGS             55      // Read or write settings
@@ -152,7 +153,6 @@ struct hashfast_info {
 	int last_die_adjusted;
 	int clock_offset;
 	int hash_voltage;                           // Hash voltage to use, in mV
-	bool set_voltage_needed;
 
 	pthread_t read_thr;
 	time_t last_restart;