I have a laptop with AMD A8-5557M APU (Radeon HD 8550G, r600) and discrete
videocard Radeon HD 8750M (radeonsi). I also have a monitor connected via a
hdmi and use it as main screen.

I use PRIME to play a game:

$ xrandr --setprovideroffloadsink 0x41 0x78
$ DRI_PRIME=1 steam

With DRI drivers version 12 it works fine, but if I update it to the recent one
(17), the game doesn't start: when I click on start button in the launcher, the
screen became black for a moment and the game exits. There is no unusual
messages in the console. I found, that if I replace
/usr/lib/dri/radeonsi_dri.so with the old one, the game works. With the
integrated video (r600) it works fine on all versions.

I reported also this to the distribution bug tracker [1], but seems this is an
upstream bug in the radeonsi driver.

[1] https://bugs.mageia.org/show_bug.cgi?id=20632