Update: - debugging issues on igt testcases - plane composition features: add primary plane improvements - suggestions of good tasks to start working on vkms

Drop: - syzkaller bug report: what triggered the warning was replaced by shmem functions at https://patchwork.freedesktop.org/patch/394614/ - overlay plane: this feature was added by https://patchwork.freedesktop.org/patch/430941/

Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Rodrigo Siqueira rodrigosiqueiramelo@gmail.com Cc: Sumera Priyadarsini sylphrenadin@gmail.com Signed-off-by: Melissa Wen melissa.srw@gmail.com --- Documentation/gpu/vkms.rst | 36 ++++++++++++++++++++++++------------ 1 file changed, 24 insertions(+), 12 deletions(-)

diff --git a/Documentation/gpu/vkms.rst b/Documentation/gpu/vkms.rst index 2c9b376da5ca..dbcb175da958 100644 --- a/Documentation/gpu/vkms.rst +++ b/Documentation/gpu/vkms.rst @@ -98,9 +98,17 @@ with VKMS maintainers. IGT better support ------------------

-- Investigate: (1) test cases on kms_plane that are failing due to timeout on - capturing CRC; (2) when running kms_flip test cases in sequence, some - successful individual test cases are failing randomly. +Debugging: + +- kms_plane: some test cases are failing due to timeout on capturing CRC; + +- kms_flip: when running test cases in sequence, some successful individual + test cases are failing randomly; when individually, some successful test + cases display in the log the following error:: + + [drm:vkms_prepare_fb [vkms]] ERROR vmap failed: -4 + +Virtual hardware (vblank-less) mode:

- VKMS already has support for vblanks simulated via hrtimers, which can be tested with kms_flip test; in some way, we can say that VKMS already mimics @@ -116,7 +124,15 @@ Add Plane Features

There's lots of plane features we could add support for:

-- Real overlay planes, not just cursor. +- Clearing primary plane: clear primary plane before plane composition (at the + start) for correctness of pixel blend ops. It also guarantees alpha channel + is cleared in the target buffer for stable crc. [Good to start] + +- ARGB format on primary plane: blend the primary plane into background with + translucent alpha. + +- Support when the primary plane isn't exactly matching the output size: blend + the primary plane into the black background.

- Full alpha blending on all planes.

@@ -129,13 +145,8 @@ There's lots of plane features we could add support for: 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. - -Prime Buffer Sharing --------------------- - -- Syzbot report - WARNING in vkms_gem_free_object: - https://syzkaller.appspot.com/bug?extid=e7ad70d406e74d8fc9d0 +all relevant igt testcases work on vkms. They are good options for internship +project.

Runtime Configuration --------------------- @@ -153,7 +164,7 @@ module. Use/Test-cases: the refresh rate.

The currently proposed solution is to expose vkms configuration through -configfs. All existing module options should be supported through configfs +configfs. All existing module options should be supported through configfs too.

Writeback support @@ -162,6 +173,7 @@ Writeback support - The writeback and CRC capture operations share the use of composer_enabled boolean to ensure vblanks. Probably, when these operations work together, composer_enabled needs to refcounting the composer state to proper work. + [Good to start]

- Add support for cloned writeback outputs and related test cases using a cloned output in the IGT kms_writeback.