✨ Use low latency flag on serial port

Might improve serial performance. Implements OctoPrint#4099
StevilKnevil · May 7, 2021 · ae60033 · ae60033
1 parent f69ab86
commit ae60033
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Showing 5 changed files with 26 additions and 0 deletions.
diff --git a/src/octoprint/server/api/settings.py b/src/octoprint/server/api/settings.py
@@ -165,6 +165,7 @@ def getSettings():
             "port": connectionOptions["portPreference"],
             "baudrate": connectionOptions["baudratePreference"],
             "exclusive": s.getBoolean(["serial", "exclusive"]),
+            "lowLatency": s.getBoolean(["serial", "lowLatency"]),
             "portOptions": connectionOptions["ports"],
             "baudrateOptions": connectionOptions["baudrates"],
             "autoconnect": s.getBoolean(["serial", "autoconnect"]),
@@ -657,6 +658,8 @@ def _saveSettings(data):
             s.setInt(["serial", "baudrate"], data["serial"]["baudrate"])
         if "exclusive" in data["serial"]:
             s.setBoolean(["serial", "exclusive"], data["serial"]["exclusive"])
+        if "lowLatency" in data["serial"]:
+            s.setBoolean(["serial", "lowLatency"], data["serial"]["lowLatency"])
         if "timeoutConnection" in data["serial"]:
             s.setFloat(
                 ["serial", "timeout", "connection"],

diff --git a/src/octoprint/settings.py b/src/octoprint/settings.py
@@ -110,6 +110,7 @@ def settings(init=False, basedir=None, configfile=None, overlays=None):
         "port": None,
         "baudrate": None,
         "exclusive": True,
+        "lowLatency": True,
         "autoconnect": False,
         "log": False,
         "timeout": {

diff --git a/src/octoprint/static/js/app/viewmodels/settings.js b/src/octoprint/static/js/app/viewmodels/settings.js
@@ -183,6 +183,7 @@ $(function () {
         self.serial_port = ko.observable();
         self.serial_baudrate = ko.observable();
         self.serial_exclusive = ko.observable();
+        self.serial_lowLatency = ko.observable();
         self.serial_portOptions = ko.observableArray([]);
         self.serial_baudrateOptions = ko.observableArray([]);
         self.serial_autoconnect = ko.observable(undefined);

diff --git a/src/octoprint/templates/dialogs/settings/serialconnection.jinja2 b/src/octoprint/templates/dialogs/settings/serialconnection.jinja2
@@ -69,6 +69,13 @@
                         </label>
                     </div>
                 </div>
+                <div class="control-group">
+                    <div class="controls">
+                        <label class="checkbox">
+                            <input type="checkbox" data-bind="checked: serial_lowLatency" id="settings-serialLowLatency"> {{ _('Request low latency mode on the serial port') }}
+                        </label>
+                    </div>
+                </div>
                 <div class="control-group">
                     <label class="control-label">{{ _('Apply parity double open workaround')}}</label>
                     <div class="controls">

diff --git a/src/octoprint/util/comm.py b/src/octoprint/util/comm.py
@@ -3685,6 +3685,20 @@ def default(_, p, b, timeout):
                 # noinspection PyProtectedMember
                 set_close_exec(serial_obj._port_handle)
 
+            if hasattr(serial_obj, "set_low_latency_mode"):
+                try:
+                    serial_obj.set_low_latency_mode(
+                        settings().getBoolean(["serial", "lowLatency"])
+                    )
+                except Exception:
+                    self._logger.exception(
+                        "Could not set low latency mode on serial port, continuing without"
+                    )
+            else:
+                self._logger.info(
+                    "Platform doesn't support low latency mode on serial port"
+                )
+
             return BufferedReadlineWrapper(serial_obj)
 
         serial_factories = list(self._serial_factory_hooks.items()) + [