Waveshare 3.5

[CoderFX]

Simply put - it doesn't work with RPi 3. But it made the screen color change from white to dark.

$ uname -a

Linux retropie 4.4.21-v7+ #911 SMP Thu Sep 15 14:22:38 BST 2016 armv7l GNU/Linux

[bes1002t]

same here, try to use it with the RPi3 with linux kernel 4.4.21.
Used the waveshare35a-overlay.dtb because I'm using a 4" display.

the color changed from white to black but that's it. No screen at all.

[swkim01]

Please read fbtft wiki.
If you want to use the display as a console, add this to the end of the line in /boot/cmdline.txt

fbcon=map:10

Otherwise, if you want to display X window, change to /dev/fb1 in /usr/share/X11/xorg.conf.d/99-fbturbo.conf, then startx.