From 7ce57e179b257f35e447971f4fb6614e3360762a Mon Sep 17 00:00:00 2001
From: Yao Wei <mwei@lxde.org>
Date: Tue, 21 Feb 2023 03:43:05 +0000
Subject: [PATCH] dix: Force update LEDs after device state update in
 EnableDevice
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This is to make sure the hardware gets the device states regardless
whether the internal state has changed or not, to overcome situations
that device LEDs are out of sync e.g. switching between VTs.

Signed-off-by: Yao Wei (魏銘廷) <yao.wei@canonical.com>
---
 dix/devices.c    |  4 ++++
 include/xkbsrv.h |  2 ++
 xkb/xkbLEDs.c    | 38 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 44 insertions(+)

diff --git a/dix/devices.c b/dix/devices.c
index f5ab17352..7150734a5 100644
--- a/dix/devices.c
+++ b/dix/devices.c
@@ -422,6 +422,10 @@ EnableDevice(DeviceIntPtr dev, BOOL sendevent)
 
     if (!IsMaster(dev) && !IsFloating(dev))
         XkbPushLockedStateToSlaves(GetMaster(dev, MASTER_KEYBOARD), 0, 0);
+
+    /* Now make sure our LEDs are in sync with the locked state */
+    XkbForceUpdateDeviceLEDs(dev);
+
     RecalculateMasterButtons(dev);
 
     /* initialise an idle timer for this device*/
diff --git a/include/xkbsrv.h b/include/xkbsrv.h
index 5b4f71f76..21cd8768d 100644
--- a/include/xkbsrv.h
+++ b/include/xkbsrv.h
@@ -505,6 +505,8 @@ extern _X_EXPORT void XkbUpdateIndicators(DeviceIntPtr /* keybd */ ,
                                           XkbEventCausePtr      /* cause */
     );
 
+extern void XkbForceUpdateDeviceLEDs(DeviceIntPtr /* keybd */);
+
 extern _X_EXPORT void XkbUpdateAllDeviceIndicators(XkbChangesPtr /* changes */,
                                                    XkbEventCausePtr /* cause */
     );
diff --git a/xkb/xkbLEDs.c b/xkb/xkbLEDs.c
index d4690dad9..2ddd7a402 100644
--- a/xkb/xkbLEDs.c
+++ b/xkb/xkbLEDs.c
@@ -434,6 +434,44 @@ XkbUpdateIndicators(DeviceIntPtr dev,
 
 /***====================================================================***/
 
+        /*
+         * void
+         * XkbForceUpdateDeviceLEDs(DeviceIntPtr dev)
+         *
+         * Force update LED states to the hardware from the device state
+         * specified by 'dev'.
+         *
+         * If 'dev' is a master device, this function will also force update
+         * its slave devices.
+         *
+         * Used if the actual LED state was externally set and need to push
+         * current state to the hardware e.g. switching between VTs.
+         */
+
+void
+XkbForceUpdateDeviceLEDs(DeviceIntPtr dev)
+{
+    DeviceIntPtr master;
+    XkbSrvLedInfoPtr sli;
+
+    if (!dev->key)
+        return;
+
+    sli = XkbFindSrvLedInfo(dev, XkbDfltXIClass, XkbDfltXIId, 0);
+    XkbDDXUpdateDeviceIndicators(dev, sli, sli->effectiveState);
+
+    if (IsMaster(dev)) {
+        master = dev;
+        nt_list_for_each_entry(dev, inputInfo.devices, next) {
+            if (!dev->key || GetMaster(dev, MASTER_KEYBOARD) != master)
+                continue;
+
+            sli = XkbFindSrvLedInfo(dev, XkbDfltXIClass, XkbDfltXIId, 0);
+            XkbDDXUpdateDeviceIndicators(dev, sli, sli->effectiveState);
+        }
+    }
+}
+
 /***====================================================================***/
 
         /*