On Mon, 30 Nov 2020, Daniel Vetter wrote: > On Mon, Nov 30, 2020 at 01:39:17PM -0500, Mikulas Patocka wrote: > > > > > > On Mon, 30 Nov 2020, Daniel Vetter wrote: > > > > > On Mon, Nov 30, 2020 at 09:31:15AM -0500, Mikulas Patocka wrote: > > > > > > > > The framebuffer driver supports programs running full-screen directly on > > > > the framebuffer console, such as web browser "links -g", image viewer > > > > "fbi", postscript+pdf viewer "fbgs", ZX Spectrum emulator "fuse-sdl", > > > > movie player "mplayer -vo fbdev". The DRM driver doesn't run them. > > > > > > Hm this should in general work on drm drivers. Without that it's clear the > > > switch-over isn't really ready yet. > > > > I fixed it with this patch two years ago: > > https://lists.freedesktop.org/archives/dri-devel/2018-June/179023.html > > > > But the patch never went through and the fb_defio feature was removed in > > the kernel 5.6 (commit d0c4fc5a4814e431c15272935c8dc973c18073aa). > > The generic fbdev emulation still has a defio implementation. We could try > to make it more efficient maybe, but it should be all there. The module > option disappeared since you now should always get it by default. Yes, it's there. I've tried to run links on the current DRM UDL driver and it displays correctly - except, that the page list gets sometimes corrupted and a crash happens. > > Without fb_defio, the only other possibility how to update the screen is > > the ioctl DRM_IOCTL_MODE_DIRTYFB. But this ioctl requires master mode, so > > user programs like "links -g" can't issue it. > > Now I'm confused, I thought you wanted to use fbdev /dev/fb* nodes? Those > should support defio. And if you want your applications to use drm > modesetting natively, they have to be drm master anyway. You can't use the > DIRTYFB ioctl to upload fbdev contents. So I'm a bit confused. > -Daniel Yes. I was confused about it too. You can't use DRM ioctls on /dev/fb. Mikulas
