On Tue, Apr 7, 2015 at 2:56 PM, Gerd Hoffmann kraxel@redhat.com wrote:
On Do, 2015-04-02 at 09:57 +0800, John Hunter wrote:
Hi Daniel, Sorry to disturb you, I realized you are a busy man of the community. So I did some work before I email you.
I submit my proposal as you suggest, convert the two virtual driver (CIRRUS and BOCHS, if I remember it right) to atomic mode-setting.
After talked with Martin Peres(the administrator of xorg on gsoc) and Gerd Hoffmann (the author of VirtIO gpu driver), we got this question, is CIRRUS suitable to convert, as qemu using cirrus considered harmful.
Short background summary on the later for everybody involved:
cirrus emulates hardware from the 90ies which simply isn't up to todays needs. The two major issues:
- It has very limited video memory. The cirrus driver does swap framebuffers in and out of video memory because of that. I suspect converting the driver to atomic modesetting will be either impossible or at least pretty difficult because of that. The limited video memory also limits the available resolutions, cirrus can't do FullHD for example.
I think at least I should give it a try. If it is really impossible to convert, then we should talk about whether we should deprecate it in the future. And I hope to treat cirrus as an test filed, it's a easier driver, so I can get into the drm kernel hacking quickly.
* cirrus can run 1024x768 only at 24bpp (not 32bpp). Which is rather
unusual these days and cirrus has display issues in xorg because it takes code paths which are not really maintained & tested any more.
cirrus isn't the default vga any more in qemu version 2.2 & newer because of these problems.
cheers, Gerd