norma-dmm: Added request timeout mechanism; docs.

[libsigrok.git] / hardware / norma-dmm / protocol.c

diff --git a/hardware/norma-dmm/protocol.c b/hardware/norma-dmm/protocol.c
index 8e1466a42df76e0a5504890cf492bd21fb233380..717ef15213142ed93080578aa4599ae7e4a1ef1b 100644 (file)
--- a/hardware/norma-dmm/protocol.c
+++ b/hardware/norma-dmm/protocol.c
@@ -17,6 +17,11 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+/** @file
+ *  Norma DM9x0/Siemens B102x DMMs driver.
+ *  @internal
+ */
+
 #include "protocol.h"
 
 SR_PRIV const struct nmadmm_req nmadmm_requests[] = {
@@ -50,6 +55,8 @@ static int nma_send_req(const struct sr_dev_inst *sdi, int req, char *params)
                return SR_ERR;
        }
 
+       devc->req_sent_at = g_get_monotonic_time();
+
        return SR_OK;
 }
 
@@ -417,9 +424,18 @@ SR_PRIV int norma_dmm_receive_data(int fd, int revents, void *cb_data)
        }
 
        /* Request next package. */
-       if (!terminating && !devc->last_req_pending) {
-               if (nma_send_req(sdi, NMADMM_REQ_STATUS, NULL) != SR_OK)
-                       return FALSE;
+       if (!terminating) {
+               if (devc->last_req_pending) {
+                       gint64 elapsed_us = g_get_monotonic_time() - devc->req_sent_at;
+                       if (elapsed_us > NMADMM_TIMEOUT_MS * 1000) {/* Timeout! */
+                               sr_spew("Request timeout!");
+                               devc->last_req_pending = FALSE;
+                       }
+               }
+               if (!devc->last_req_pending) {
+                       if (nma_send_req(sdi, NMADMM_REQ_STATUS, NULL) != SR_OK)
+                               return FALSE;
+               }
        }
 
        return TRUE;