Switchable graphics and radeon PX runtime

[Takashi Iwai]

Hi Alex,

we've got a few bug reports about the behavior of radeon driver on
machines with Intel+AMD "switchable graphics" (no Muxless).  So far,
it seems that the sane only way to make the machine working is to get
back to the old vgaswitcheroo behavior via radeon.runpm=0.  Without
it, radeon GPU gives a spurious output as connected, eventually
crashes GNOME.  (Also, from the nature of the switchable graphics,
vgaswitcheroo looks more intuitive to me.)

How are such machines supposed to work with the recent system?  Is PX
wrongly detected on them, or something else missing?

If it shouldn't be treated as PX, would we put them in
radeon_px_quirk_list[]?  Of course, this won't scale.  So, any better
way to detect such machines?


thanks,

Takashi