OLS Improvements

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

@@ -511,6 +511,8 @@ SR_PRIV int ols_receive_data(int fd, int revents, void *cb_data)
 			devc->rle_count = 0;
 		}
 	} else {
+		unsigned int num_pre_trigger_samples;
+
 		/*
 		 * This is the main loop telling us a timeout was reached, or
 		 * we've acquired all the samples we asked for -- we're done.
@@ -541,7 +543,9 @@ SR_PRIV int ols_receive_data(int fd, int revents, void *cb_data)
 			 * A trigger was set up, so we need to tell the frontend
 			 * about it.
 			 */
-			if (devc->trigger_at_smpl > 0) {
+			if (devc->trigger_at_smpl > 0 &&
+			    (unsigned int)devc->trigger_at_smpl <=
+				    devc->num_samples) {
 				/* There are pre-trigger samples, send those first. */
 				packet.type = SR_DF_LOGIC;
 				packet.payload = &logic;
@@ -556,17 +560,22 @@ SR_PRIV int ols_receive_data(int fd, int revents, void *cb_data)
 		}
 
 		/* Send post-trigger / all captured samples. */
-		int num_pre_trigger_samples = devc->trigger_at_smpl ==
-							      OLS_NO_TRIGGER ?
-							    0 :
-							    devc->trigger_at_smpl;
-		packet.type = SR_DF_LOGIC;
-		packet.payload = &logic;
-		logic.length =
-			(devc->num_samples - num_pre_trigger_samples) * 4;
-		logic.unitsize = 4;
-		logic.data = devc->raw_sample_buf + num_pre_trigger_samples * 4;
-		sr_session_send(sdi, &packet);
+		num_pre_trigger_samples =
+			devc->trigger_at_smpl == OLS_NO_TRIGGER ?
+				      0 :
+				      MIN((unsigned int)devc->trigger_at_smpl,
+				    devc->num_samples);
+		if (devc->num_samples > num_pre_trigger_samples) {
+			packet.type = SR_DF_LOGIC;
+			packet.payload = &logic;
+			logic.length =
+				(devc->num_samples - num_pre_trigger_samples) *
+				4;
+			logic.unitsize = 4;
+			logic.data = devc->raw_sample_buf +
+				     num_pre_trigger_samples * 4;
+			sr_session_send(sdi, &packet);
+		}
 
 		g_free(devc->raw_sample_buf);
 		devc->raw_sample_buf = 0;