On Fri, Jun 10, 2022 at 08:54:03AM +0000, Simon Ser wrote: > I agree with what others have replied, just adding a few more details. > > On Thursday, June 9th, 2022 at 21:39, Zack Rusin <zackr@xxxxxxxxxx> wrote: > > > virtualized drivers send drm_kms_helper_hotplug_event which sends a HOTPLUG=1 > > event with a changed preferred width/height > > (Note: and the "hotplug_mode_update" property is set to 1.) > > > suggested_x and suggested_y properties > > These come with their own set of issues. They are poorly defined, but it seems > like they describe a position in physical pixel coordinates. Compositors don't > use physical pixel coordinates to organize their outputs, instead they use > logical coordinates. For instance, a HiDPI 4k screen with a scale of 2 will > take up 1920x1080 logical pixels. There is no way to convert physical pixel > coordinates to logical pixel coordinates in the general case, because there's > no "global scale factor". So suggested_x/y are incompatible with the way > compositors work. I dropped a request for a proper doc section that explains all the virtualized kms driver stuff. I think we should also put in a "limitations" part there and just spec that any kind of scaling is a no-go on these (and that drivers better validate this is the case). -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch
