for some reason network down. one simple cgminer command:

"cgminer -o 127.0.0.1:8888 -O fa:ke --avalon-options 115200:32:10:50:256"
can idle the avalon for safe power and protect chip

driver-avalon.c

@@ -618,14 +618,11 @@ static bool avalon_detect_one(const char *devpath)
 	info->temp_old = 0;
 	info->frequency = frequency;
 
-	/* Do something for failed reset ? */
-	if (0) {
 	/* Set asic to idle mode after detect */
 	avalon_idle(avalon);
 	avalon->device_fd = -1;
 
 	avalon_close(fd);
-	}
 	return true;
 }