XMir now on vmwgfx
Daniel van Vugt
daniel.van.vugt at canonical.com
Fri Dec 20 02:25:44 UTC 2013
Excellent work, thanks.
The two people best placed to answer your questions are now on vacation,
but I shall try;
1) There is no explicit message that DRM mastership has been dropped.
Mir will just block in the page flip while the (Mir) server is no longer
But that happens after the drop of mastership so there's still a
potential race between the server dropping it, and the DDX rendering.
Worst case is that the DDX could render 2 frames before filling the
queue and then no more will be requested until the server resumes. Is it
more than 2 extraneous frames you're seeing? Or is two still a problem
for the DDX? Do we need something like this?...
/* DDX code in which mastership won't be dropped */
2) The pixel format of the XMir surface appears to be fixed at
mir_pixel_format_xrgb_8888 right now. See:
3) I'm not sure. But the region comes from xmir_window_get_dirty(), here:
On 19/12/13 21:08, Thomas Hellstrom wrote:
> I just pushed a branch "hosted" to xf86-video-vmware that enables XMir
> (and also XWayland). It will probably not be part of next release which
> might happen very soon, but probably with the next release. I'm not sure
> what X support on Mir will look like in the end, but all XMir - specific
> code is confined to a single file, so it should be easy to change if needed.
> Performance seems OK, given that the vmwgfx driver fakes pageflipping
> with multiple fullscreen copies. This also means that performance of
> XMir compared to bare Xorg might look a bit bad.
> A couple of outstanding issues:
> 1) When Mir VT switches, I guess it drops DRM master. Still, from what I
> can tell, the XMir driver is not informed, and may attempt to continue
> to render using the drm file-descriptor. Is there a way to inform the
> driver about this?
> 2) I'd like to have a way to get the pixel format of the XMir copy
> buffer. I guess it's whatever GBM gives Mir for a given depth, but is it
> to assume that the depth of the XMir copy buffer is identical to the
> depth of the source window drawable?
> 3) Is the region given as the second argument to xmir_window_proc
> relative to the source window drawable or relative to the underlying pixmap?
> Thomas Hellstrom
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