X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=src%2Fhardware%2Fhp-3457a%2Fapi.c;h=64fdab54deef5cbc875d57f3b3c07fbb84a498c5;hb=755793e991c4d429f99254f23008bfddb89d8e00;hp=599cad74279d06466ca73a55b60b8c820b0bc160;hpb=dd7a72ea697a172032f5473b0ddff5e8d47222f4;p=libsigrok.git

diff --git a/src/hardware/hp-3457a/api.c b/src/hardware/hp-3457a/api.c
index 599cad74..64fdab54 100644
--- a/src/hardware/hp-3457a/api.c
+++ b/src/hardware/hp-3457a/api.c
@@ -245,7 +245,6 @@ static int config_get(uint32_t key, GVariant **data,
 static int config_set(uint32_t key, GVariant *data,
 	const struct sr_dev_inst *sdi, const struct sr_channel_group *cg)
 {
-	int ret;
 	enum sr_mq mq;
 	enum sr_mqflag mq_flags;
 	struct dev_context *devc;
@@ -255,7 +254,6 @@ static int config_set(uint32_t key, GVariant *data,
 
 	devc = sdi->priv;
 
-	ret = SR_OK;
 	switch (key) {
 	case SR_CONF_LIMIT_SAMPLES:
 		devc->limit_samples = g_variant_get_uint64(data);
@@ -265,17 +263,15 @@ static int config_set(uint32_t key, GVariant *data,
 		mq = g_variant_get_uint32(tuple_child);
 		tuple_child = g_variant_get_child_value(data, 1);
 		mq_flags = g_variant_get_uint64(tuple_child);
-		ret = hp_3457a_set_mq(sdi, mq, mq_flags);
 		g_variant_unref(tuple_child);
-		break;
+		return hp_3457a_set_mq(sdi, mq, mq_flags);
 	case SR_CONF_ADC_POWERLINE_CYCLES:
-		ret = hp_3457a_set_nplc(sdi, g_variant_get_double(data));
-		break;
+		return hp_3457a_set_nplc(sdi, g_variant_get_double(data));
 	default:
-		ret = SR_ERR_NA;
+		return SR_ERR_NA;
 	}
 
-	return ret;
+	return SR_OK;
 }
 
 static int config_list(uint32_t key, GVariant **data,
@@ -363,8 +359,13 @@ static int dev_acquisition_start(const struct sr_dev_inst *sdi)
 		return SR_ERR_ARG;
 	}
 
-	devc->current_channel = devc->active_channels->data;
 	devc->num_active_channels = g_slist_length(devc->active_channels);
+	if (!devc->num_active_channels) {
+		sr_err("Need at least one active channel!");
+		g_slist_free(devc->active_channels);
+		return SR_ERR_ARG;
+	}
+	devc->current_channel = devc->active_channels->data;
 
 	hp_3457a_select_input(sdi, front_selected ? CONN_FRONT : CONN_REAR);