Merge tag 'drm-misc-next-2018-11-07' of git://anongit.freedesktop.org/drm/drm-misc into drm-next

drm-misc-next for v4.21, part 1:

UAPI Changes:
- Add syncobj timeline support to drm.

Cross-subsystem Changes:
- Remove shared fence staging in dma-buf's fence object, and allow
  reserving more than 1 fence and add more paranoia when debugging.
- Constify infoframe functions in video/hdmi.

Core Changes:
- Add vkms todo, and a lot of assorted doc fixes.
- Drop transitional helpers and convert drivers to use drm_atomic_helper_shutdown().
- Move atomic state helper functions to drm_atomic_state_helper.[ch]
- Refactor drm selftests, and add new tests.
- DP MST atomic state cleanups.
- Drop EXPORT_SYMBOL from drm leases.
- Lease cleanups and fixes.
- Create render node for vgem.

Driver Changes:
- Fix build failure in imx without fbdev emulation.
- Add rotation quirk for GPD win2 panel.
- Add support for various CDTech panels, Banana Pi Panel, DLC1010GIG,
  Olimex LCD-O-LinuXino, Samsung S6D16D0, Truly NT35597 WQXGA,
  Himax HX8357D, simulated RTSM AEMv8.
- Add dw_hdmi support to rockchip driver.
- Fix YUV support in vc4.
- Fix resource id handling in virtio.
- Make rockchip use dw-mipi-dsi bridge driver, and add dual dsi support.
- Advertise that tinydrm only supports DRM_FORMAT_MOD_LINEAR.
- Convert many drivers to use atomic helpers, and drm_fbdev_generic_setup().
- Add Mali linear tiled formats, and enable them in the Mali-DP driver.
- Add support for H6 DE3 mixer 0, DW HDMI, HDMI PHY and TCON TOP.
- Assorted driver cleanups and fixes.

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/be7ebd91-edd9-8fa4-4286-1c57e3165113@linux.intel.com

1 files changed, 99 insertions, 2 deletions

diff --git a/Documentation/gpu/vkms.rst b/Documentation/gpu/vkms.rst
index 0a6ea6216e41..7dfc349a4508 100644
--- a/Documentation/gpu/vkms.rst
+++ b/Documentation/gpu/vkms.rst
@@ -10,8 +10,8 @@
 TODO
 ====
 
-CRC API
--------
+CRC API Improvements
+--------------------
 
 - Optimize CRC computation ``compute_crc()`` and plane blending ``blend()``
 
@@ -22,3 +22,100 @@ CRC API
 
 - Add igt test to check extreme alpha values i.e. fully opaque and fully
   transparent (intermediate values are affected by hw-specific rounding modes).
+
+Vblank issues
+-------------
+
+Some IGT test cases are failing. Need to analyze why and fix the issues:
+
+- plain-flip-fb-recreate
+- plain-flip-ts-check
+- flip-vs-blocking-wf-vblank
+- plain-flip-fb-recreate-interruptible
+- flip-vs-wf_vblank-interruptible
+
+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.