Hi, This is an updated RFC series introducing a new connector type: DRM_MODE_CONNECTOR_WRITEBACK See v1 here: [1] Writeback connectors are used to expose the memory writeback engines found in some display controllers, which can write a CRTC's composition result to a memory buffer. This is useful e.g. for testing, screen-recording, screenshots, wireless display, display cloning, memory-to-memory composition. Writeback connectors are given a WRITEBACK_FB_ID property (which acts slightly differently to FB_ID, so gets a new name), as well as PIXEL_FORMATS and PIXEL_FORMATS_SIZE to list the supported writeback formats, and OUT_FENCE_PTR to be used for out-fences. The semantics of writeback connectors have been changed significantly since v1, based largely on Daniel's feedback. Now, a writeback connector can only be attached to a CRTC if it has a framebuffer attached and vice-versa. The writeback framebuffer applies only to a single atomic commit, and userspace can never read back the value of WRITEBACK_FB_ID. This makes writeback a "one-shot" operation, it must be re-armed every time it is to be used. Patch 1 introduces the actual connector type and the infrastructure around it. Patches 2-6 add a writeback connector for mali-dp. Patches 7-9 add support for writeback out-fences, based on Gustavo Padovan's v5 series [2] for adding explicit fencing. As always, I look forward to any comments. Thanks, Brian [1] http://www.mail-archive.com/linux-kernel@xxxxxxxxxxxxxxx/msg1247574.html [2] http://www.mail-archive.com/linux-kernel@xxxxxxxxxxxxxxx/msg1253822.html Changes since v1, based on Daniel and Eric's comments: - The writeback framebuffer is no longer persistent across commits - Removed the client cap, made the connector report disconnected instead - Added drm_writeback.c for central connector initialization and documentation - Added support for out-fences - Added core checks for writeback connectors, e.g. disallowing a framebuffer with no CRTC - Mali-DP doesn't require a full modeset to enable/disable the writeback connector --- Brian Starkey (8): drm: Add writeback connector type drm: mali-dp: Clear CVAL when leaving config mode drm: mali-dp: Rename malidp_input_format drm: mali-dp: Add RGB writeback formats for DP550/DP650 drm: mali-dp: Add writeback connector drm: atomic: factor out common out-fence operations drm: writeback: Add out-fences for writeback connectors drm: mali-dp: Add writeback out-fence support Liviu Dudau (1): drm: mali-dp: Add support for writeback on DP550/DP650 Documentation/gpu/drm-kms.rst | 9 + drivers/gpu/drm/Makefile | 2 +- drivers/gpu/drm/arm/Makefile | 1 + drivers/gpu/drm/arm/malidp_crtc.c | 21 +++ drivers/gpu/drm/arm/malidp_drv.c | 28 +++- drivers/gpu/drm/arm/malidp_drv.h | 7 + drivers/gpu/drm/arm/malidp_hw.c | 149 +++++++++++++---- drivers/gpu/drm/arm/malidp_hw.h | 27 ++- drivers/gpu/drm/arm/malidp_mw.c | 313 +++++++++++++++++++++++++++++++++++ drivers/gpu/drm/arm/malidp_mw.h | 28 ++++ drivers/gpu/drm/arm/malidp_planes.c | 8 +- drivers/gpu/drm/arm/malidp_regs.h | 15 ++ drivers/gpu/drm/drm_atomic.c | 218 +++++++++++++++++++++--- drivers/gpu/drm/drm_atomic_helper.c | 8 + drivers/gpu/drm/drm_connector.c | 4 +- drivers/gpu/drm/drm_writeback.c | 237 ++++++++++++++++++++++++++ include/drm/drm_atomic.h | 3 + include/drm/drm_connector.h | 26 +++ include/drm/drm_crtc.h | 20 +++ include/drm/drm_writeback.h | 21 +++ include/uapi/drm/drm_mode.h | 1 + 21 files changed, 1076 insertions(+), 70 deletions(-) create mode 100644 drivers/gpu/drm/arm/malidp_mw.c create mode 100644 drivers/gpu/drm/arm/malidp_mw.h create mode 100644 drivers/gpu/drm/drm_writeback.c create mode 100644 include/drm/drm_writeback.h -- 1.7.9.5 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
