X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=src%2Fhardware%2Fhantek-dso%2Fprotocol.c;h=34a3935b9fd4fa6e36f3ceab8197652f2629e625;hb=HEAD;hp=39d87c4433bb316564e0cdff84df818b76c2f808;hpb=d3f14af7ed07ba5b7e2c1af7c11614454021abbe;p=libsigrok.git

diff --git a/src/hardware/hantek-dso/protocol.c b/src/hardware/hantek-dso/protocol.c
index 39d87c44..34a3935b 100644
--- a/src/hardware/hantek-dso/protocol.c
+++ b/src/hardware/hantek-dso/protocol.c
@@ -130,7 +130,9 @@ SR_PRIV int dso_open(struct sr_dev_inst *sdi)
 			/*
 			 * Check device by its physical USB bus/port address.
 			 */
-			usb_get_port_path(devlist[i], connection_id, sizeof(connection_id));
+			if (usb_get_port_path(devlist[i], connection_id, sizeof(connection_id)) < 0)
+				continue;
+
 			if (strcmp(sdi->connection_id, connection_id))
 				/* This is not the one. */
 				continue;
@@ -273,8 +275,10 @@ static int dso2250_set_trigger_samplerate(const struct sr_dev_inst *sdi)
 	memset(cmdstring, 0, sizeof(cmdstring));
 	/* Command */
 	cmdstring[0] = CMD_2250_SET_TRIGGERSOURCE;
-	sr_dbg("Trigger source %s.", devc->triggersource);
-	if (!strcmp("CH2", devc->triggersource))
+	sr_dbg("Trigger source %s.", devc->triggersource ? : "<none>");
+	if (!devc->triggersource)
+		tmp = 0;
+	else if (!strcmp("CH2", devc->triggersource))
 		tmp = 3;
 	else if (!strcmp("CH1", devc->triggersource))
 		tmp = 2;
@@ -324,7 +328,8 @@ static int dso2250_set_trigger_samplerate(const struct sr_dev_inst *sdi)
 	}
 
 	tmp = base / devc->samplerate;
-	if (tmp) {
+	/* Downsample only if really necessary */
+	if (tmp > 1) {
 		/* Downsampling on */
 		cmdstring[2] |= 2;
 		/* Downsampler = 1comp((Base / Samplerate) - 2)
@@ -418,8 +423,10 @@ SR_PRIV int dso_set_trigger_samplerate(const struct sr_dev_inst *sdi)
 	cmdstring[0] = CMD_SET_TRIGGER_SAMPLERATE;
 
 	/* Trigger source */
-	sr_dbg("Trigger source %s.", devc->triggersource);
-	if (!strcmp("CH2", devc->triggersource))
+	sr_dbg("Trigger source %s.", devc->triggersource ? : "<none>");
+	if (!devc->triggersource)
+		tmp = 2;
+	else if (!strcmp("CH2", devc->triggersource))
 		tmp = 0;
 	else if (!strcmp("CH1", devc->triggersource))
 		tmp = 1;
@@ -665,7 +672,7 @@ static int dso_set_relays(const struct sr_dev_inst *sdi)
 	if (devc->coupling[1] != COUPLING_AC)
 		relays[6] = ~relays[6];
 
-	if (!strcmp(devc->triggersource, "EXT"))
+	if (devc->triggersource && strcmp(devc->triggersource, "EXT") == 0)
 		relays[7] = ~relays[7];
 
 	if (sr_log_loglevel_get() >= SR_LOG_DBG) {