From: Keith Packard <keithp@keithp.com>
Date: Sat, 10 Apr 2010 00:51:01 +0000 (-0700)
Subject: Only have the slave return a packet if it received one.
X-Git-Tag: debian/0.6+171+g9394393~1
X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=commitdiff_plain;h=9394393c24c0a96b94319f2d0aa78fb498a121c9

Only have the slave return a packet if it received one.

When the receive is aborted to switch modes, it's important to not
immediately re-acquire the radio and try to send a packet as the
aborting thread won't know to kick the receiver again.

This prevents the 'C' command from locking up as it tries to stop the
packet slave before turning on the transmitter.

Signed-off-by: Keith Packard <keithp@keithp.com>
---

diff --git a/src/ao_packet_slave.c b/src/ao_packet_slave.c
index 4c947fbf..e03ebdc3 100644
--- a/src/ao_packet_slave.c
+++ b/src/ao_packet_slave.c
@@ -20,12 +20,15 @@
 void
 ao_packet_slave(void)
 {
+	uint8_t	status;
+
 	ao_radio_set_packet();
 	ao_tx_packet.addr = ao_serial_number;
 	ao_tx_packet.len = AO_PACKET_SYN;
 	while (ao_packet_enable) {
-		ao_packet_recv();
-		ao_packet_send();
+		status = ao_packet_recv();
+		if (status & AO_DMA_DONE)
+			ao_packet_send();
 	}
 	ao_exit();
 }