mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-24 05:04:00 +08:00
8c77b22243
Remove the list of broken tests on VKMS solved by patchset https://patchwork.freedesktop.org/series/55994/ Signed-off-by: Shayenne Moura <shayenneluzmoura@gmail.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20190206193157.3b53ipdxtcqc4hv4@smtp.gmail.com
111 lines
3.7 KiB
ReStructuredText
111 lines
3.7 KiB
ReStructuredText
.. _vkms:
|
|
|
|
==========================================
|
|
drm/vkms Virtual Kernel Modesetting
|
|
==========================================
|
|
|
|
.. kernel-doc:: drivers/gpu/drm/vkms/vkms_drv.c
|
|
:doc: vkms (Virtual Kernel Modesetting)
|
|
|
|
TODO
|
|
====
|
|
|
|
CRC API Improvements
|
|
--------------------
|
|
|
|
- Optimize CRC computation ``compute_crc()`` and plane blending ``blend()``
|
|
|
|
- Use the alpha value to blend vaddr_src with vaddr_dst instead of
|
|
overwriting it in ``blend()``.
|
|
|
|
- Add igt test to check cleared alpha value for XRGB plane format.
|
|
|
|
- Add igt test to check extreme alpha values i.e. fully opaque and fully
|
|
transparent (intermediate values are affected by hw-specific rounding modes).
|
|
|
|
Runtime Configuration
|
|
---------------------
|
|
|
|
We want to be able to reconfigure vkms instance without having to reload the
|
|
module. Use/Test-cases:
|
|
|
|
- Hotplug/hotremove connectors on the fly (to be able to test DP MST handling of
|
|
compositors).
|
|
|
|
- Configure planes/crtcs/connectors (we'd need some code to have more than 1 of
|
|
them first).
|
|
|
|
- Change output configuration: Plug/unplug screens, change EDID, allow changing
|
|
the refresh rate.
|
|
|
|
The currently proposed solution is to expose vkms configuration through
|
|
configfs. All existing module options should be supported through configfs too.
|
|
|
|
Add Plane Features
|
|
------------------
|
|
|
|
There's lots of plane features we could add support for:
|
|
|
|
- Real overlay planes, not just cursor.
|
|
|
|
- Full alpha blending on all planes.
|
|
|
|
- Rotation, scaling.
|
|
|
|
- Additional buffer formats, especially YUV formats for video like NV12.
|
|
Low/high bpp RGB formats would also be interesting.
|
|
|
|
- Async updates (currently only possible on cursor plane using the legacy cursor
|
|
api).
|
|
|
|
For all of these, we also want to review the igt test coverage and make sure all
|
|
relevant igt testcases work on vkms.
|
|
|
|
Writeback support
|
|
-----------------
|
|
|
|
Currently vkms only computes a CRC for each frame. Once we have additional plane
|
|
features, we could write back the entire composited frame, and expose it as:
|
|
|
|
- Writeback connector. This is useful for testing compositors if you don't have
|
|
hardware with writeback support.
|
|
|
|
- As a v4l device. This is useful for debugging compositors on special vkms
|
|
configurations, so that developers see what's really going on.
|
|
|
|
Prime Buffer Sharing
|
|
--------------------
|
|
|
|
We already have vgem, which is a gem driver for testing rendering, similar to
|
|
how vkms is for testing the modeset side. Adding buffer sharing support to vkms
|
|
allows us to test them together, to test synchronization and lots of other
|
|
features. Also, this allows compositors to test whether they work correctly on
|
|
SoC chips, where the display and rendering is very often split between 2
|
|
drivers.
|
|
|
|
Output Features
|
|
---------------
|
|
|
|
- Variable refresh rate/freesync support. This probably needs prime buffer
|
|
sharing support, so that we can use vgem fences to simulate rendering in
|
|
testing. Also needs support to specify the EDID.
|
|
|
|
- Add support for link status, so that compositors can validate their runtime
|
|
fallbacks when e.g. a Display Port link goes bad.
|
|
|
|
- All the hotplug handling describe under "Runtime Configuration".
|
|
|
|
Atomic Check using eBPF
|
|
-----------------------
|
|
|
|
Atomic drivers have lots of restrictions which are not exposed to userspace in
|
|
any explicit form through e.g. possible property values. Userspace can only
|
|
inquiry about these limits through the atomic IOCTL, possibly using the
|
|
TEST_ONLY flag. Trying to add configurable code for all these limits, to allow
|
|
compositors to be tested against them, would be rather futile exercise. Instead
|
|
we could add support for eBPF to validate any kind of atomic state, and
|
|
implement a library of different restrictions.
|
|
|
|
This needs a bunch of features (plane compositing, multiple outputs, ...)
|
|
enabled already to make sense.
|