ols: Receive many bytes in a row

We're talking about 20 kB, so there's little need to go back to the event
loop in between. But there's also no reason why we should go back to the
event loop if we can read more data immediately.

Author: v1ne

src/hardware/openbench-logic-sniffer/protocol.c

@@ -397,6 +397,7 @@ SR_PRIV int ols_receive_data(int fd, int revents, void *cb_data)
 	uint32_t sample;
 	unsigned int i, j, num_changroups;
 	unsigned char byte;
+	gboolean received_a_byte;
 
 	(void)fd;
 
@@ -416,9 +417,10 @@ SR_PRIV int ols_receive_data(int fd, int revents, void *cb_data)
 		}
 	}
 
-	if (revents == G_IO_IN) {
-		if (serial_read_nonblocking(serial, &byte, 1) != 1)
-			return FALSE;
+	received_a_byte = FALSE;
+	while (revents == G_IO_IN &&
+	       serial_read_nonblocking(serial, &byte, 1) == 1) {
+		received_a_byte = TRUE;
 		devc->cnt_rx_bytes++;
 
 		devc->raw_sample[devc->raw_sample_size++] = byte;
@@ -527,6 +529,8 @@ SR_PRIV int ols_receive_data(int fd, int revents, void *cb_data)
 			devc->rle_count = 0;
 		}
 	}
+	if (revents == G_IO_IN && !received_a_byte)
+		return FALSE;
 
 process_and_forward:
 	if (revents != G_IO_IN ||