Revamp signal handling in eglfs/linuxfb

Go back to the pipe-based signal handling. signalfd() introduces more harm than good
and is a regression for applications that install their own signal handlers.

Simplify the somewhat overcomplicated suspend (Ctrl+Z) logic too. There is no need for
requiring a callback. Just enable/disable the keyboard and cursor on suspend and resume
and emit the signals. Backends (like kms) may then perform additional steps, if they
choose to do so.

Task-number: QTBUG-48384
Change-Id: Ifd52de89c59915a2e0be6bf5ebc6f2ff1728eb50
Reviewed-by: Louai Al-Khanji <louai.al-khanji@theqtcompany.com>

1 files changed, 4 insertions, 5 deletions

diff --git a/src/platformsupport/fbconvenience/qfbvthandler_p.h b/src/platformsupport/fbconvenience/qfbvthandler_p.h
index 3681def9f0..91eba248fe 100644
--- a/src/platformsupport/fbconvenience/qfbvthandler_p.h
+++ b/src/platformsupport/fbconvenience/qfbvthandler_p.h
@@ -59,23 +59,22 @@ public:
     QFbVtHandler(QObject *parent = 0);
     ~QFbVtHandler();
 
-    void suspend();
-
 signals:
     void interrupted();
-    void suspendRequested();
+    void aboutToSuspend();
     void resumed();
 
 private slots:
     void handleSignal();
 
 private:
-    void restoreKeyboard();
+    void setKeyboardEnabled(bool enable);
     void handleInt();
+    static void signalHandler(int sigNo);
 
     int m_tty;
     int m_oldKbdMode;
-    int m_signalFd;
+    int m_sigFd[2];
     QSocketNotifier *m_signalNotifier;
 };