Hello Maxime, Maxime Ripard wrote: > Hi, > > On Thu, Feb 16, 2017 at 01:28:24PM +0100, Tobias Jakobi wrote: >> Hello, >> >> I'm not sure if I'm missing something here, but I don't see how this is >> supposed to work. >> >> This just multiplies the height of the drm_mode_fb_cmd2 object with the >> number of buffers. Let's say I have width=1024, height=768, then now I >> have a framebuffer which has height=2304 (in the num_buffers=3 case). At >> some point this FB is set as the primary plane, giving us a 1024x2304 >> mode. I don't think that this is intended. >> >> In my opinion this multi-buffer thing should touch drm_mode_fb_cmd2 at >> all. The underlying BO should be larger, but not the FB itself. If this >> is supposed to work, then the fbdev helpers should create as many FBs as >> there are buffers, and then offset each of these FB into the BO. > > This only increases the virtual resolution, not the visible one. hmm, OK, I guess I need to test this again then. The last time I checked such an approach was on vanilla-4.7.y IIRC. And there it failed miserably. >> What I'm also not seeing is code that handles the fbdev's virtual >> resolutions. After all num_buffers should only increase those. Same for >> the panning ioctl(). > > This is already implemented through drm_fb_helper_pan_display. Thanks, I'll take a look! With best wishes, Tobias > > Maxime > _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
