rigol-ds: improve robustness in samplerate getting code path

[libsigrok.git] / src / hardware / rigol-ds / api.c

diff --git a/src/hardware/rigol-ds/api.c b/src/hardware/rigol-ds/api.c
index 95de8f6a0d7b30339a7fd6756ba3d4bfe556d0f6..632c95963cb75e517e6d7abe3cbff783e6cbee70 100644 (file)
--- a/src/hardware/rigol-ds/api.c
+++ b/src/hardware/rigol-ds/api.c
@@ -883,6 +883,7 @@ static int dev_acquisition_start(const struct sr_dev_inst *sdi)
        GSList *l;
        char *cmd;
        int protocol;
+       int ret;
 
        scpi = sdi->conn;
        devc = sdi->priv;
@@ -1021,20 +1022,27 @@ static int dev_acquisition_start(const struct sr_dev_inst *sdi)
 
        devc->channel_entry = devc->enabled_channels;
 
-       if (devc->data_source == DATA_SOURCE_LIVE)
-               devc->sample_rate = analog_frame_size(sdi) / 
+       if (devc->data_source == DATA_SOURCE_LIVE) {
+               devc->sample_rate = analog_frame_size(sdi) /
                        (devc->timebase * devc->model->series->num_horizontal_divs);
-       else {
+       } else {
                float xinc;
-               if (devc->model->series->protocol >= PROTOCOL_V3 && 
-                               sr_scpi_get_float(sdi->conn, "WAV:XINC?", &xinc) != SR_OK) {
-                       sr_err("Couldn't get sampling rate");
+               if (devc->model->series->protocol < PROTOCOL_V3) {
+                       sr_err("Cannot get samplerate (below V3).");
+                       return SR_ERR;
+               }
+               ret = sr_scpi_get_float(sdi->conn, "WAV:XINC?", &xinc);
+               if (ret != SR_OK) {
+                       sr_err("Cannot get samplerate (WAV:XINC? failed).");
+                       return SR_ERR;
+               }
+               if (!xinc) {
+                       sr_err("Cannot get samplerate (zero XINC value).");
                        return SR_ERR;
                }
                devc->sample_rate = 1. / xinc;
        }
 
-
        if (rigol_ds_capture_start(sdi) != SR_OK)
                return SR_ERR;