kingst-la2016: rephrase USB renum code path after firmware upload

[libsigrok.git] / src / hardware / kingst-la2016 / api.c

diff --git a/src/hardware/kingst-la2016/api.c b/src/hardware/kingst-la2016/api.c
index c5a661088adebacb5dc0c624249e0e720c3cfc88..4d501450e9a3fa40a412dbeaea2efb8a592e7d01 100644 (file)
--- a/src/hardware/kingst-la2016/api.c
+++ b/src/hardware/kingst-la2016/api.c
@@ -142,7 +142,7 @@ static GSList *scan(struct sr_dev_driver *di, GSList *options)
        unsigned int i, j;
        const char *conn;
        char connection_id[64];
-       int64_t fw_updated;
+       uint64_t fw_uploaded;
        unsigned int dev_addr;
 
        drvc = di->context;
@@ -196,7 +196,7 @@ static GSList *scan(struct sr_dev_driver *di, GSList *options)
                sdi->status = SR_ST_INITIALIZING;
                sdi->connection_id = g_strdup(connection_id);
 
-               fw_updated = 0;
+               fw_uploaded = 0;
                dev_addr = libusb_get_device_address(devlist[i]);
                if (des.iProduct != 2) {
                        sr_info("Device at '%s' has no firmware loaded.", connection_id);
@@ -207,7 +207,7 @@ static GSList *scan(struct sr_dev_driver *di, GSList *options)
                                g_free(sdi);
                                continue;
                        }
-                       fw_updated = g_get_monotonic_time();
+                       fw_uploaded = g_get_monotonic_time();
                        /* Will re-enumerate. Mark as "unknown address yet". */
                        dev_addr = 0xff;
                }
@@ -222,7 +222,7 @@ static GSList *scan(struct sr_dev_driver *di, GSList *options)
 
                devc = g_malloc0(sizeof(struct dev_context));
                sdi->priv = devc;
-               devc->fw_updated = fw_updated;
+               devc->fw_uploaded = fw_uploaded;
                devc->threshold_voltage_idx = 0;
                devc->threshold_voltage = logic_threshold_value[devc->threshold_voltage_idx];
 
@@ -336,43 +336,42 @@ static int la2016_dev_open(struct sr_dev_inst *sdi)
 static int dev_open(struct sr_dev_inst *sdi)
 {
        struct dev_context *devc;
-       int64_t timediff_us, timediff_ms;
-       uint64_t reset_done;
-       uint64_t now;
+       uint64_t reset_done, now, elapsed_ms;
        int ret;
 
        devc = sdi->priv;
 
        /*
-        * When the sigrok driver recently uploaded firmware, wait for
-        * the FX2 to re-enumerate. Deal with the condition that the
-        * MCU can take some 2000ms to be gone from the bus before it
-        * re-appears executing the recently uploaded firmware.
+        * When the sigrok driver recently has uploaded MCU firmware,
+        * then wait for the FX2 to re-enumerate. Allow the USB device
+        * to vanish before it reappears. Timeouts are rough estimates
+        * after all, the imprecise time of the last check (potentially
+        * executes after the total check period) simplifies code paths
+        * with optional diagnostics. And increases the probability of
+        * successfully detecting "late/slow" devices.
         */
-       ret = SR_ERR;
-       if (devc->fw_updated > 0) {
+       if (devc->fw_uploaded) {
                sr_info("Waiting for device to reset after firmware upload.");
-               reset_done = devc->fw_updated;
-               reset_done += 1800 * 1000; /* 1.8 seconds */
                now = g_get_monotonic_time();
-               if (reset_done > now)
+               reset_done = devc->fw_uploaded + RENUM_GONE_DELAY_MS * 1000;
+               if (now < reset_done)
                        g_usleep(reset_done - now);
-               timediff_ms = 0;
-               while (timediff_ms < MAX_RENUM_DELAY_MS) {
-                       g_usleep(200 * 1000);
-
-                       timediff_us = g_get_monotonic_time() - devc->fw_updated;
-                       timediff_ms = timediff_us / 1000;
-
-                       if ((ret = la2016_dev_open(sdi)) == SR_OK)
+               do {
+                       now = g_get_monotonic_time();
+                       elapsed_ms = (now - devc->fw_uploaded) / 1000;
+                       sr_spew("Waited %" PRIu64 "ms.", elapsed_ms);
+                       ret = la2016_dev_open(sdi);
+                       if (ret == SR_OK) {
+                               devc->fw_uploaded = 0;
                                break;
-                       sr_spew("Waited %" PRIi64 "ms.", timediff_ms);
-               }
+                       }
+                       g_usleep(RENUM_POLL_INTERVAL_MS * 1000);
+               } while (elapsed_ms < RENUM_CHECK_PERIOD_MS);
                if (ret != SR_OK) {
                        sr_err("Device failed to re-enumerate.");
                        return SR_ERR;
                }
-               sr_info("Device came back after %" PRIi64 "ms.", timediff_ms);
+               sr_info("Device came back after %" PRIi64 "ms.", elapsed_ms);
        } else {
                ret = la2016_dev_open(sdi);
        }