glamor / xf86-video-modesetting

[coypu%sdf.org@localhost]

So, xf86-video-intel has issues on old GMA cards with SNA.
xf86-video-modesetting doesn't share those issues, but requires glamor
to be performant.

I thought I'd have another look, this time with a radeon HD5450.
adding this /etc/xorg.conf:
Section "Device"
	Identifier    "Configured Video Device"
	Driver        "modesetting"
EndSection

Surprisingly, glamor is already attempted out of the box
(II) modeset(0): glamor X acceleration enabled on AMD CEDAR (DRM 2.43.0 / 10.0.59, LLVM 9.0.0)

Unfortunately it has very violent display issues (text in terminal looks
wrong, glxgears doesn't display anything).

Looking at the warnings,
(WW) modeset(0): DRI2: glamor lacks support for pixmap import/export

Apparently this is a warning that occurs when dri3 is not enabled.

So I'm taking back my hints to others that we should work on
xf86-video-modesetting for a while. Will have to DRM update first.