On Tue, Jan 10, 2023 at 10:28:39AM +0100, Gerd Hoffmann wrote: > On Fri, Jan 06, 2023 at 10:35:15AM +0100, Daniel Vetter wrote: > > On Fri, Jan 06, 2023 at 09:56:40AM +0100, Gerd Hoffmann wrote: > > > On Thu, Nov 17, 2022 at 05:30:54PM -0800, Vivek Kasireddy wrote: > > > > Setting this property will allow the userspace to look for new modes or > > > > position info when a hotplug event occurs. > > > > > > This works just fine for modes today. > > > > > > I assume this is this need to have userspace also check for position > > > info updates added by patch #1)? > > > > What does this thing even do? Quick grep says qxl and vmwgfx also use > > this, but it's not documented anywhere, and it's also not done with any > > piece of common code. Which all looks really fishy. > > It's again a virtualization-specific thing. On physical hardware you > typically have no idea which of your two monitors stands left and which > stands right. On virtual hardware the host knows how the two windows > for the two heads are arranged and can pass on that information to the > guest. suggested_x/y properties added by patch #1 do pass that > information to userspace so the display server can arrange things > correctly without manual invention. Yeah suggested_x/y I know about. Would still be good to fix the documentation situation for that. > I have no clue though why this hotplug_mode_update property exists in > the first place and why mutter checks it. IMHO mutter could just check > for suggested_x/y directly. This one is the complete wtf here. I have no idea why this exists. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch
