Post by Ilia Mirkin Post by Marek Olšák
Mario, feel free to push your patches if you haven't yet. (except the
just started 10 minutes ago with rebasing my current patchset against
mesa master. Will need some adjustments and retesting against i965.
I was also just "sort of done" with a mesa/gallium 10 bit version. I
think i'll submit rev 3 later today or tomorrow and maybe we'll need to
sort this out then, what goes where. I'll compare with Mareks branch...
The current state of my series for AMD here is that radeon-kms + ati-ddx
works nicely under exa (and with a slightly patched weston), but the
ati-ddx also needed some small patches which i have to send out. On
amdgpu-kms i know it works under my patched weston branch.
What is completely missing is glamor support, ergo support for at least
amdgpu-ddx and modesetting-ddx -- and xwayland.
Post by Ilia Mirkin Post by Marek Olšák
For AMD, I applied Mario's patches (except Wayland - that didn't
What's the status of Glamor?
Do we have patches for xf86-video-amdgpu? The closed should have
10-bit support, meaning we should have DDX patches already somewhere,
Somewhere there must be some, as the amdgpu-pro driver with the
proprietary libGL supported depth 30 at least in some version i tested
earlier this year?
Post by Ilia Mirkin
I'd like to test this out with nouveau as well... do I understand
correctly that I shouldn't need anything special to check if it
basically works? i.e. I apply the patches, start Xorg in bpp=30 mode,
and then if glxgears works then I'm done? Is there a good way that I'm
really in 30bpp mode as far as all the software is concerned? (I don't
have a colorimeter or whatever fancy hw to *really* tell the
difference, although I do have a "deep color" TV.) If used with a
24bpp display, is the hw supposed to dither somehow?x
nouveau is quite a bit work to do and not so clear how to proceed.
My current series does do proper xrgb2101010 / argb2101010 rendering
under gallium on both nv50 and nvc0 (Tested under GeForce 9600 for
tesla, GTX 970 and 1050 for maxwell and pascal). I used PRIME render
offload under both DRI3/Present and Wayland/Weston with both intel and
amd as display gpus, so i know the drivers work together properly and
nouveau-gallium renders correctly.
The display side for native scanout on Nvidia is somewhat broken atm.:
1. Since Linux 4.10 with the switch of nouveau-kms to atomic
modesetting, using drmAddFB() with depth/bpp 30/32 maps to xrgb2101010
format, but nouveau-kms doesn't support xrgb2101010, so setting Xorg to
depth 30 will end in a server-abort with modesetting failure. nouveau
before Linux 4.10 mapped 30/32 to xbgr2101010 which seems to be
supported since nv50. If i boot with a < 4.10 kernel i get a picture at
least on the old GeForce 9600 and GT330M.
If i hack nouveau-ddx to use a xrgb2101010 color channel mask (red in
msb's, blue in lsbs) instead of the correct xbgr2101010 mask, then i can
get nouveau-gallium to render 10 bits, but of course with swapped red
and blue channels. Switching dithering on via xrandr allows to get
rendered 10 bit images to get to a 8 bpc display, as confirmed via
colorimeter. I hope a deep color TV might work without dithering.
gpu's since kepler gk104 support xrgb2101010 scanout. With a hacked
nouveau-kms i can get the maxwell and pascal cards to accept
xrgb2101010, but the display is beyond weird. So far i couldn't make
much sense of the pixeltrash -- some of it remotely resembles a desktop,
but something is going wrong badly. Also the xbgr2101010 mode doesn't
work correct. The same is true for Wayland+Weston and even if i run
Weston with pixman, keeping Mesa out of the picture. So nouveau-kms
needs some work for all modern nvidia gpu's. Gamma table handling
changed quite a bit, so maybe something is wrong there.
2. We might also need some work for exa on nvc0+, but it's not clear
what problems are caused by kernel side, and what in exa.
3. In principle the clean solution for nouveau would be to upgrade the
ddx to drmAddFB2 ioctl, and use xbgr2101010 scanout to support
everything back to nv50+, but everything we have in X or Wayland is
meant for xrgb2101010 not xbgr2101010. And we run into ambiguities of
what, e.g., a depth 30 pixmap means in some extensions like
glx_texture_form_pixmap. And the GLX extension generally seems to have
unresolved problems with ARGB formats instead of ABGR formats, which is
why Mesa doesn't expose ARGB by default -- only on Android atm.
So on nouveau everything except the gallium bits is quite a bit messy at
the moment, but the gallium bits work according to my testing.