On Fri, Nov 11, 2016 at 12:07:29PM -0500, Alex Deucher wrote: > On Fri, Nov 11, 2016 at 12:00 PM, Ville Syrjälä > <ville.syrjala@xxxxxxxxxxxxxxx> wrote: > > On Thu, Nov 03, 2016 at 02:31:43PM +0200, ville.syrjala@xxxxxxxxxxxxxxx wrote: > >> From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > >> > >> This reverts commit a68362fe3e84fcbedd49939aa200519aa5410135. > >> > >> Adding new mode flags willy nilly breaks existing userspace. We need to > >> coordinate this better, potentially with a new client cap that only > >> exposes the aspect ratio flags when userspace is prepared for them > >> (similar to what we do with stereo 3D modes). > > > > As a demonstration here's the change in the xrandr mode list after doing > > the revert: > > > > HDMI2 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 700mm x 390mm > > - 1920x1080 60.00*+ > > - 1920x1080i 60.00 50.00 > > + 1920x1080 60.00*+ 50.00 59.94 30.00 25.00 24.00 29.97 23.98 > > + 1920x1080i 60.00 50.00 59.94 > > 1600x1200 60.00 > > 1680x1050 59.88 > > 1280x1024 75.02 60.02 > > @@ -13,30 +13,29 @@ > > 1360x768 60.02 > > 1280x800 59.91 > > 1152x864 75.00 > > - 1280x720 60.00 50.00 > > + 1280x720 60.00 50.00 59.94 > > 1024x768 75.03 70.07 60.00 > > 832x624 74.55 > > 800x600 72.19 75.00 60.32 > > - 640x480 75.00 72.81 66.67 59.94 > > + 720x576 50.00 > > + 720x480 60.00 59.94 > > + 640x480 75.00 72.81 66.67 60.00 59.94 > > 720x400 70.08 > > > > This was with sna, which does this: > > #define KNOWN_MODE_FLAGS ((1<<14)-1) > > if (mode->status == MODE_OK && kmode->flags & ~KNOWN_MODE_FLAGS) > > mode->status = MODE_BAD; /* unknown flags => unhandled */ > > so all the modes with an aspect ratio just vanished. > > > > -modesetting and -ati on the other hand just copy over the unknown > > bits into the xrandr mode structure, which sounds dubious at best: > > mode->Flags = kmode->flags; //& FLAG_BITS; > > I've not checked what damage it can actually cause. > > What problems could this cause? As I wrote, I haven't analyzed the potential damage from this. Either something in the server might go wonky, or maybe we even leak that stuff over the protocol all the way to the clients? Not sure. > Presumably the kernel driver has > validated the modes already or they wouldn't showing up in the first > place. Or is your concern that something in the xserver itself may > barf on the new flags? > > Alex -- Ville Syrjälä Intel OTC _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
