On Wed, 02 May 2018, Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote: > Quoting Ville Syrjälä (2018-05-02 17:14:21) >> On Wed, May 02, 2018 at 04:57:09PM +0100, Chris Wilson wrote: >> > Quoting Ville Syrjälä (2018-05-02 16:52:41) >> > > On Wed, May 02, 2018 at 04:33:30PM +0100, Chris Wilson wrote: >> > > > Quoting Ville Syrjala (2018-04-26 17:30:15) >> > > > > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> >> > > > > >> > > > > During state readout we first read out the pipe src size, store >> > > > > that information in the user mode h/vdisplay, but later on we overwrite >> > > > > that with the actual crtc timings. That makes our read out crtc state >> > > > > inconsistent with itself when the BIOS has enabled the panel fitter to >> > > > > scale the pipe contents. Let's preserve the pipe src size based >> > > > > information in the user mode to make things consistent again. >> > > > >> > > > The question I don't feel answered is: If this is the BIOS mode, why >> > > > aren't we filling it from get_hw_state? >> > > >> > > I suppose the answer is that we're only filling out the bare minimum >> > > of information during the basic readout. That is everything we need >> > > for intel_pipe_config_compare() to do its job. Later on we fill the >> > > gaps to make the state actually presentable to userspace. We don't >> > > have to do that if the state we read out isn't actually going to be >> > > exposed to userspace. >> > > >> > > I suppose we could consider doing a more thorough job up front, but >> > > I think we'd need to spend some though on eg. the handling of the >> > > mode blob. We probably wouldn't want userspace to gain access to >> > > our short lived internal mode blob created from the read out state. >> > >> > Will we run into a problem where we say the current mode is 800x600, but >> > is in fact 1024x768 scaledfrom 800x600? E.g. if we for whatever reason >> > want to switch to a real 800x600 mode? >> >> Seems unlikely that the real 800x600 mode would have the same blanking >> lengths and clock as the 1024x768 mode. So we should end up with a full >> modeset. > > Right, that's going to be pretty weird and unlikely. > > Reviewed-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> >From [1], Tested-by: Larry Finger <Larry.Finger@xxxxxxxxxxxx> BR, Jani. [1] http://mid.mail-archive.com/4371fd28-49fb-f019-1fc3-f1318b9562fd@xxxxxxxxxxxx > > I guess you would want to throw in a comment as to why this is a special > case... But this whole pass is pretty special inheritance code... > -Chris > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
