On Wed, 27 Mar 2013 13:49:47 +0100 Daniel Vetter <daniel at ffwll.ch> wrote: > On Wed, Mar 27, 2013 at 3:09 AM, Jesse Barnes <jbarnes at virtuousgeek.org> wrote: > > If for example the BIOS fb is too small for the dual pipe config we detect, > > we may have valid timings and such, but no fb. The pfit case also hits this > > path (though currently only fastboots if you hack your mode clock to match). > > But even when the BIOS fb is to small and the BIOS config uses the > pfit, we /should/ have an fb around. Looking a bit closer I think the > confusion stems from you reading out the adjusted mode, but treating > it like the requested mode. I think it'd be much more solid if we > store the read-out mode in the adjusted_mode (won't work otherwise > with hw state cross-checking anyway), and then do two comparisons > here: Yeah, there's an fb, but it may not be what we want. So we don't allocate it and thus crtc->fb is empty. > - Does the request mode (plus everything else) match? If so, just do > an fb_set_base call. > - Does the adjusted mode match (plus the entire output routing ofc)? > That means there's either the vga plane or a pfit in-between which we > don't like. If possible we can then play some tricks to avoid the full > modeset. Right, I'm trying to play tricks here for sure. > The reason that I'm a bit freaked about about your change here is that > in a lot of places we treat crtc->fb == NULL as "no mode set". So I > fear we're breaking a few too many assumptions here with that hack, > and it simply needs more thought about what we should actually check. Yeah I was worried about that too. Maybe we should use crtc->active for that everywhere? With the modeset rework and pipe config stuff, we should be able to drop this in favor of something that looks at the pipe_config and figures out the minimal mode set sequence required. -- Jesse Barnes, Intel Open Source Technology Center
