Update 'linux rasp pi4 X11 EGLFS'

linux-rasp-pi4-X11-EGLFS.md

@@ -25,4 +25,13 @@ sudo apt-get install libudev-dev libinput-dev libts-dev libxcb-xinerama0-dev lib
 ```
 ../configure -release -opengl es2 -make libs -nomake tests -nomake examples -skip wayland -skip qtscript -skip qtwebengine -skip location -device linux-rasp-pi3-vc4-g++ -device-option CROSS_COMPILE=/media/mehran/extra4/Qt5Pi4/raspi/rpi-gcc-8.3.0/bin/arm-linux-gnueabihf- -sysroot /media/mehran/extra4/Qt5Pi4/raspi/sysroot -opensource -confirm-license -make libs -prefix /usr/local/qt5pi -extprefix /media/mehran/extra4/Qt5Pi4/raspi/qt5pi -hostprefix /media/mehran/extra4/Qt5Pi4/raspi/qt5 -v -no-use-gold-linker
 
-```
+```
+
+### Fix:
+```
+Running on a software rasterizer (LLVMpipe), expect limited performance.
+```
+```
+sudo gpasswd -a pi render
+```
+https://bugreports.qt.io/browse/QTBUG-76889