evdevkeyboard: Try opening as read-write first

switchLed writes to the device, and so O_RDONLY cannot be correct.

Change-Id: If79814804bcd3c6fb01617be9f1a73e54b9563bd
Fixes: QTBUG-80653
Reviewed-by: Andy Nichols <andy.nichols@qt.io>
(cherry picked from commit 9c05fdac81d5fe0d3007ba55cfddf4eb99183153)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

2 files changed, 6 insertions, 1 deletions

diff --git a/src/platformsupport/input/evdevkeyboard/qevdevkeyboardhandler.cpp b/src/platformsupport/input/evdevkeyboard/qevdevkeyboardhandler.cpp
index c0d58f39a0..5d0121fbdb 100644
--- a/src/platformsupport/input/evdevkeyboard/qevdevkeyboardhandler.cpp
+++ b/src/platformsupport/input/evdevkeyboard/qevdevkeyboardhandler.cpp
@@ -138,7 +138,11 @@ std::unique_ptr<QEvdevKeyboardHandler> QEvdevKeyboardHandler::create(const QStri
 
     qCDebug(qLcEvdevKey, "Opening keyboard at %ls", qUtf16Printable(device));
 
-    QFdContainer fd(qt_safe_open(device.toLocal8Bit().constData(), O_RDONLY | O_NDELAY, 0));
+    QFdContainer fd(qt_safe_open(device.toLocal8Bit().constData(), O_RDWR | O_NDELAY, 0));
+    if (fd.get() < 0) {
+        qCDebug(qLcEvdevKey, "Keyboard device could not be opened as read-write, trying read-only");
+        fd.reset(qt_safe_open(device.toLocal8Bit().constData(), O_RDONLY | O_NDELAY, 0));
+    }
     if (fd.get() >= 0) {
         ::ioctl(fd.get(), EVIOCGRAB, grab);
         if (repeatDelay > 0 && repeatRate > 0) {
diff --git a/src/platformsupport/input/evdevkeyboard/qevdevkeyboardhandler_p.h b/src/platformsupport/input/evdevkeyboard/qevdevkeyboardhandler_p.h
index 5060212159..0b2d41944a 100644
--- a/src/platformsupport/input/evdevkeyboard/qevdevkeyboardhandler_p.h
+++ b/src/platformsupport/input/evdevkeyboard/qevdevkeyboardhandler_p.h
@@ -143,6 +143,7 @@ public:
 
     int release() noexcept { int result = m_fd; m_fd = -1; return result; }
     void reset() noexcept;
+    void reset(int fd) { reset(); m_fd = fd; }
 };
 
 class QEvdevKeyboardHandler : public QObject