Summary ======= This series of patches refactor some vkms components in order to introduce new formats to the planes and writeback connector.
Now in the blend function, the plane's pixels are converted to ARGB16161616 and then blended together.
The CRC is calculated based on the ARGB1616161616 buffer. And if required, this buffer is copied/converted to the writeback buffer format.
And to handle the pixel conversion, new functions were added to convert from a specific format to ARGB16161616 (the reciprocal is also true).
Tests ===== This patch series was tested using the following igt tests: -t ".*kms_plane.*" -t ".*kms_writeback.*" -t ".*kms_cursor_crc*" -t ".*kms_flip.*"
New tests passing ------------------- - pipe-A-cursor-size-change - pipe-A-cursor-alpha-transparent
Performance ----------- It's running slightly faster than the current implementation.
Results running the IGT[1] test `igt@kms_cursor_crc@pipe-a-cursor-512x512-onscreen` ten times:
| Frametime | |:--------------------------------------------:| | Implementation | Current | This commit | |:---------------:|:---------:|:--------------:| | frametime range | 9~22 ms | 10~22 ms | | Average | 11.4 ms | 12.32 ms |
Memory consumption ================== It consumes less memory than the current implementation in the common case (more detail in the commit message).
| Memory consumption (output dimensions) | |:--------------------------------------:| | Current | This patch | |:------------------:|:-----------------:| | Width * Heigth | 2 * Width |
[1] IGT commit id: bc3f6833a12221a46659535dac06ebb312490eb4
XRGB to ARGB behavior ===================== During the development, I decided to always fill the alpha channel of the output pixel whenever the conversion from a format without an alpha channel to ARGB16161616 is necessary. Therefore, I ignore the value received from the XRGB and overwrite the value with 0xFFFF.
Primary plane and CRTC size =========================== This patch series reworks the blend function to accept a primary plane with a different size and position from CRTC. Because now we need to fill the background, we had a loss in performance with this change
Alpha channel output for XRGB formats ===================================== There's still an open question about which value the writeback alpha channel should be for XRGB formats. The current igt test implementation is expecting the channel to not be change. But it's not entirely clear if this should be the behavior followed by vkms (or any other driver).
Open issue: https://gitlab.freedesktop.org/drm/igt-gpu-tools/-/issues/118 ---
Igor Torrente (9): drm: vkms: Replace hardcoded value of `vkms_composer.map` to DRM_FORMAT_MAX_PLANES drm: vkms: Rename `vkms_composer` to `vkms_frame_info` drm: drm_atomic_helper: Add a new helper to deal with the writeback connector validation drm: vkms: get the reference to `drm_framebuffer` instead if coping it drm: vkms: Add fb information to `vkms_writeback_job` drm: vkms: Refactor the plane composer to accept new formats drm: vkms: Supports to the case where primary plane doesn't match the CRTC drm: vkms: Adds XRGB_16161616 and ARGB_1616161616 formats drm: vkms: Add support to the RGB565 format
Documentation/gpu/vkms.rst | 7 +- drivers/gpu/drm/drm_atomic_helper.c | 39 ++++ drivers/gpu/drm/vkms/Makefile | 1 + drivers/gpu/drm/vkms/vkms_composer.c | 314 ++++++++++++-------------- drivers/gpu/drm/vkms/vkms_drv.h | 39 +++- drivers/gpu/drm/vkms/vkms_formats.c | 300 ++++++++++++++++++++++++ drivers/gpu/drm/vkms/vkms_formats.h | 12 + drivers/gpu/drm/vkms/vkms_plane.c | 50 ++-- drivers/gpu/drm/vkms/vkms_writeback.c | 39 +++- include/drm/drm_atomic_helper.h | 3 + 10 files changed, 584 insertions(+), 220 deletions(-) create mode 100644 drivers/gpu/drm/vkms/vkms_formats.c create mode 100644 drivers/gpu/drm/vkms/vkms_formats.h