rdtech-um: concentrate poll period handling in one spot

The handling of "command sent at ..." and the emission of periodic poll
requests is non-trivial, and was scattered around different locations.
Concentrate all of the time scaling and delta calculation and updating
internal state into a single spot, and allow callers to force the first
emission when desired (acquisition start needs this). Which eliminates
repeated calls into the microseconds getter.

Not advancing the last checkpoint, and keep sending requests until
successful transmission, remains identical to the previous version of
the implementation. In practise transmit errors are rare.

diff --git a/src/hardware/rdtech-um/api.c b/src/hardware/rdtech-um/api.c
index a6c5f6976445470c416772342c73977dca678ecb..863ba972cd99ea16807a709a05645db1ff45bf6a 100644 (file)
--- a/src/hardware/rdtech-um/api.c
+++ b/src/hardware/rdtech-um/api.c
@@ -156,7 +156,7 @@ static int dev_acquisition_start(const struct sr_dev_inst *sdi)
        serial_source_add(sdi->session, serial, G_IO_IN, 50,
                rdtech_um_receive_data, (void *)sdi);
 
-       return rdtech_um_poll(sdi);
+       return rdtech_um_poll(sdi, TRUE);
 }
 
 static struct sr_dev_driver rdtech_um_driver_info = {

diff --git a/src/hardware/rdtech-um/protocol.c b/src/hardware/rdtech-um/protocol.c
index 6c56e245faa5f21576a1354e9fc21c65e8f14d2c..e2afc67d8a9f4c2117212485ed8450de3f865fc0 100644 (file)
--- a/src/hardware/rdtech-um/protocol.c
+++ b/src/hardware/rdtech-um/protocol.c
@@ -147,12 +147,21 @@ SR_PRIV const struct rdtech_um_profile *rdtech_um_probe(struct sr_serial_dev_ins
        return p;
 }
 
-SR_PRIV int rdtech_um_poll(const struct sr_dev_inst *sdi)
+SR_PRIV int rdtech_um_poll(const struct sr_dev_inst *sdi, gboolean force)
 {
        struct dev_context *devc;
+       int64_t now, elapsed;
        struct sr_serial_dev_inst *serial;
        uint8_t request;
 
+       /* Check for expired intervals or forced requests. */
+       devc = sdi->priv;
+       now = g_get_monotonic_time() / 1000;
+       elapsed = now - devc->cmd_sent_at;
+       if (!force && elapsed < UM_POLL_PERIOD_MS)
+               return SR_OK;
+
+       /* Send another poll request. Update interval only on success. */
        serial = sdi->conn;
        request = UM_CMD_POLL;
        if (serial_write_blocking(serial, &request, sizeof(request),
@@ -160,9 +169,7 @@ SR_PRIV int rdtech_um_poll(const struct sr_dev_inst *sdi)
                sr_err("Unable to send poll request.");
                return SR_ERR;
        }
-
-       devc = sdi->priv;
-       devc->cmd_sent_at = g_get_monotonic_time() / 1000;
+       devc->cmd_sent_at = now;
 
        return SR_OK;
 }
@@ -228,7 +235,6 @@ SR_PRIV int rdtech_um_receive_data(int fd, int revents, void *cb_data)
        struct sr_dev_inst *sdi;
        struct dev_context *devc;
        struct sr_serial_dev_inst *serial;
-       int64_t now, elapsed;
 
        (void)fd;
 
@@ -247,11 +253,7 @@ SR_PRIV int rdtech_um_receive_data(int fd, int revents, void *cb_data)
                return TRUE;
        }
 
-       now = g_get_monotonic_time() / 1000;
-       elapsed = now - devc->cmd_sent_at;
-
-       if (elapsed > UM_POLL_PERIOD_MS)
-               rdtech_um_poll(sdi);
+       (void)rdtech_um_poll(sdi, FALSE);
 
        return TRUE;
 }

diff --git a/src/hardware/rdtech-um/protocol.h b/src/hardware/rdtech-um/protocol.h
index 159031a7885c286a4f28683dbf3cf484e0f0bf27..dfe1cd75642421812454ddb93e5dba80027fe3bb 100644 (file)
--- a/src/hardware/rdtech-um/protocol.h
+++ b/src/hardware/rdtech-um/protocol.h
@@ -51,6 +51,6 @@ struct dev_context {
 
 SR_PRIV const struct rdtech_um_profile *rdtech_um_probe(struct sr_serial_dev_inst *serial);
 SR_PRIV int rdtech_um_receive_data(int fd, int revents, void *cb_data);
-SR_PRIV int rdtech_um_poll(const struct sr_dev_inst *sdi);
+SR_PRIV int rdtech_um_poll(const struct sr_dev_inst *sdi, gboolean force);
 
 #endif