Remove hashfast write thread for all writes can be done from scanwork without added complexity.

driver-hashfast.c

@@ -368,20 +368,8 @@ static void *hf_read(void *arg)
 	struct hashfast_info *info = hashfast->device_data;
 
 	while (likely(!hashfast->shutdown)) {
-
-	}
-	return NULL;
 	}
 
-static void *hf_write(void *arg)
-{
-	struct thr_info *thr = (struct thr_info *)arg;
-	struct cgpu_info *hashfast = thr->cgpu;
-	struct hashfast_info *info = hashfast->device_data;
-
-	while (likely(!hashfast->shutdown)) {
-
-	}
 	return NULL;
 }
 
@@ -392,13 +380,8 @@ static bool hashfast_prepare(struct thr_info *thr)
 	struct timeval now;
 
 	mutex_init(&info->lock);
-	mutex_init(&info->write_mutex);
-	if (pthread_cond_init(&info->write_cond, NULL))
-		quit(1, "Failed to pthread_cond_init in hashfast_prepare");
 	if (pthread_create(&info->read_thr, NULL, hf_read, (void *)thr))
 		quit(1, "Failed to pthread_create read thr in hashfast_prepare");
-	if (pthread_create(&info->write_thr, NULL, hf_write, (void *)thr))
-		quit(1, "Failed to pthread_create write thr in hashfast_prepare");
 
 	cgtime(&now);
 	get_datestamp(hashfast->init, sizeof(hashfast->init), &now);
@@ -427,7 +410,6 @@ static void hashfast_shutdown(struct thr_info *thr)
 	struct hashfast_info *info = hashfast->device_data;
 
 	pthread_join(info->read_thr, NULL);
-	pthread_join(info->write_thr, NULL);
 }
 
 struct device_drv hashfast_drv = {

driver-hashfast.h

@@ -51,9 +51,6 @@ struct hashfast_info {
 	uint16_t hash_sequence_tail;                // Follows device_sequence_tail around to free work
 
 	pthread_t read_thr;
-	pthread_t write_thr;
-	pthread_mutex_t write_mutex;
-	pthread_cond_t write_cond;
 };
 
 #endif /* USE_HASHFAST */