diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-03-08 08:23:15 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-03-08 08:23:15 -0800 |
| commit | 851ca779d110f694b5d078bc4af06d3ad37169e8 (patch) | |
| tree | 3d03de09e44ef02a6f73924f32fa21646347e64e /Documentation/gpu/afbc.rst | |
| parent | b5dd0c658c31b469ccff1b637e5124851e7a4a1c (diff) | |
| parent | 4b057e73f28f1df13b77b77a52094238ffdf8abd (diff) | |
Merge tag 'drm-next-2019-03-06' of git://anongit.freedesktop.org/drm/drm
Pull drm updates from Dave Airlie:
"This is the main drm pull request for the 5.1 merge window.
The big changes I'd highlight are:
- nouveau has HMM support now, there is finally an in-tree user so we
can quieten down the rip it out people.
- i915 now enables fastboot by default on Skylake+
- Displayport Multistream support has been refactored and should
hopefully be more reliable.
Core:
- header cleanups aiming towards removing drmP.h
- dma-buf fence seqnos to 64-bits
- common helper for DP mst hotplug for radeon,i915,amdgpu + new
refcounting scheme
- MST i2c improvements
- drm_syncobj_cb removal
- ARM FB compression fourcc
- P010 + P016 fourcc
- allwinner tiled format modifier
- i2c over aux I2C_M_STOP support
- DRM_AUTH handling fixes
TTM:
- ref/unref renaming
New driver:
- ARM komeda display driver
scheduler:
- refactor mirror list handling
- rework hw fence processing
- 0 run queue entity fix
bridge:
- TI DS90C185 LVDS bridge
- thc631lvdm83d bridge improvements
- cadence + allwinner DSI ported to generic phy
panels:
- Sitronix ST7701 panel
- Kingdisplay KD097D04
- LeMaker BL035-RGB-002
- PDA 91-00156-A0
- Innolux EE101IA-01D
i915:
- Enable fastboot by default on SKL+/VLV/CHV
- Export RPCS configuration for ICL media driver
- Coffelake PCI ID
- CNL clocks setup fixes
- ACPI/PMIC support for MIPI/DSI
- Per-engine WA init for all engines
- Shrinker locking fixes
- Kerneldoc updates
- Lots of ring improvements and reset fixes
- Coffeelake GVT Support
- VFIO GVT EDID Region support
- runtime PM wakeref tracking
- ILK->IVB primary plane enable delays
- userptr mutex locking fixes
- DSI fixes
- LVDS/TV cleanups
- HW readout fixes
- LUT robustness fixes
- ICL display and watermark fixes
- gem mmap race fix
amdgpu:
- add scheduled dependencies interface
- DCC on scanout surfaces
- vega10/20 BACO support
- Multiple IH rings on soc15
- XGMI locking fixes
- DC i2c/aux cleanups
- runtime SMU debug interface
- Kexec improvmeents
- SR-IOV fixes
- DC freesync + ABM fixes
- GDS fixes
- GPUVM fixes
- vega20 PCIE DPM switching fixes
- Context priority handling fixes
radeon:
- fix missing break in evergreen parser
nouveau:
- SVM support via HMM
msm:
- QCOM Compressed modifier support
exynos:
- s5pv210 rotator support
imx:
- zpos property support
- pending update fixes
v3d:
- cache flush improvments
vc4:
- reflection support
- HDMI overscan support
tegra:
- CEC refactoring
- HDMI audio fixes
- Tegra186 prep work
- SOR crossbar device tree fixes
sun4i:
- implicit fencing support
- YUV and scalar support improvements
- A23 support
- tiling fixes
atmel-hlcdc:
- clipping and rotation property fixes
qxl:
- BO and PRIME improvements
- generic fbdev emulation
dw-hdmi:
- HDMI 2.0 2160p
- YUV420 ouput
rockchip:
- implicit fencing support
- reflection proerties
virtio-gpu:
- use generic fbdev emulation
tilcdc:
- cpufreq vs crtc init fix
rcar-du:
- R8A774C0 support
- D3/E3 RGB output routing fixes and DPAD0 support
- RA87744 LVDS support
bochs:
- atomic and generic fbdev emulation
- ID mismatch error on bochs load
meson:
- remove firmware fbs"
* tag 'drm-next-2019-03-06' of git://anongit.freedesktop.org/drm/drm: (1130 commits)
drm/amd/display: Use vrr friendly pageflip throttling in DC.
drm/imx: only send commit done event when all state has been applied
drm/imx: allow building under COMPILE_TEST
drm/imx: imx-tve: depend on COMMON_CLK
drm/imx: ipuv3-plane: add zpos property
drm/imx: ipuv3-plane: add function to query atomic update status
gpu: ipu-v3: prg: add function to get channel configure status
gpu: ipu-v3: pre: add double buffer status readback
drm/amdgpu: Bump amdgpu version for context priority override.
drm/amdgpu/powerplay: fix typo in BACO header guards
drm/amdgpu/powerplay: fix return codes in BACO code
drm/amdgpu: add missing license on baco files
drm/bochs: Fix the ID mismatch error
drm/nouveau/dmem: use dma addresses during migration copies
drm/nouveau/dmem: use physical vram addresses during migration copies
drm/nouveau/dmem: extend copy function to allow direct use of physical addresses
drm/nouveau/svm: new ioctl to migrate process memory to GPU memory
drm/nouveau/dmem: device memory helpers for SVM
drm/nouveau/svm: initial support for shared virtual memory
drm/nouveau: prepare for enabling svm with existing userspace interfaces
...
Diffstat (limited to 'Documentation/gpu/afbc.rst')
| -rw-r--r-- | Documentation/gpu/afbc.rst | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/Documentation/gpu/afbc.rst b/Documentation/gpu/afbc.rst new file mode 100644 index 000000000000..4d38dc49d105 --- /dev/null +++ b/Documentation/gpu/afbc.rst @@ -0,0 +1,235 @@ +.. SPDX-License-Identifier: GPL-2.0+ + +=================================== + Arm Framebuffer Compression (AFBC) +=================================== + +AFBC is a proprietary lossless image compression protocol and format. +It provides fine-grained random access and minimizes the amount of +data transferred between IP blocks. + +AFBC can be enabled on drivers which support it via use of the AFBC +format modifiers defined in drm_fourcc.h. See DRM_FORMAT_MOD_ARM_AFBC(*). + +All users of the AFBC modifiers must follow the usage guidelines laid +out in this document, to ensure compatibility across different AFBC +producers and consumers. + +Components and Ordering +======================= + +AFBC streams can contain several components - where a component +corresponds to a color channel (i.e. R, G, B, X, A, Y, Cb, Cr). +The assignment of input/output color channels must be consistent +between the encoder and the decoder for correct operation, otherwise +the consumer will interpret the decoded data incorrectly. + +Furthermore, when the lossless colorspace transform is used +(AFBC_FORMAT_MOD_YTR, which should be enabled for RGB buffers for +maximum compression efficiency), the component order must be: + + * Component 0: R + * Component 1: G + * Component 2: B + +The component ordering is communicated via the fourcc code in the +fourcc:modifier pair. In general, component '0' is considered to +reside in the least-significant bits of the corresponding linear +format. For example, COMP(bits): + + * DRM_FORMAT_ABGR8888 + + * Component 0: R(8) + * Component 1: G(8) + * Component 2: B(8) + * Component 3: A(8) + + * DRM_FORMAT_BGR888 + + * Component 0: R(8) + * Component 1: G(8) + * Component 2: B(8) + + * DRM_FORMAT_YUYV + + * Component 0: Y(8) + * Component 1: Cb(8, 2x1 subsampled) + * Component 2: Cr(8, 2x1 subsampled) + +In AFBC, 'X' components are not treated any differently from any other +component. Therefore, an AFBC buffer with fourcc DRM_FORMAT_XBGR8888 +encodes with 4 components, like so: + + * DRM_FORMAT_XBGR8888 + + * Component 0: R(8) + * Component 1: G(8) + * Component 2: B(8) + * Component 3: X(8) + +Please note, however, that the inclusion of a "wasted" 'X' channel is +bad for compression efficiency, and so it's recommended to avoid +formats containing 'X' bits. If a fourth component is +required/expected by the encoder/decoder, then it is recommended to +instead use an equivalent format with alpha, setting all alpha bits to +'1'. If there is no requirement for a fourth component, then a format +which doesn't include alpha can be used, e.g. DRM_FORMAT_BGR888. + +Number of Planes +================ + +Formats which are typically multi-planar in linear layouts (e.g. YUV +420), can be encoded into one, or multiple, AFBC planes. As with +component order, the encoder and decoder must agree about the number +of planes in order to correctly decode the buffer. The fourcc code is +used to determine the number of encoded planes in an AFBC buffer, +matching the number of planes for the linear (unmodified) format. +Within each plane, the component ordering also follows the fourcc +code: + +For example: + + * DRM_FORMAT_YUYV: nplanes = 1 + + * Plane 0: + + * Component 0: Y(8) + * Component 1: Cb(8, 2x1 subsampled) + * Component 2: Cr(8, 2x1 subsampled) + + * DRM_FORMAT_NV12: nplanes = 2 + + * Plane 0: + + * Component 0: Y(8) + + * Plane 1: + + * Component 0: Cb(8, 2x1 subsampled) + * Component 1: Cr(8, 2x1 subsampled) + +Cross-device interoperability +============================= + +For maximum compatibility across devices, the table below defines +canonical formats for use between AFBC-enabled devices. Formats which +are listed here must be used exactly as specified when using the AFBC +modifiers. Formats which are not listed should be avoided. + +.. flat-table:: AFBC formats + + * - Fourcc code + - Description + - Planes/Components + + * - DRM_FORMAT_ABGR2101010 + - 10-bit per component RGB, with 2-bit alpha + - Plane 0: 4 components + * Component 0: R(10) + * Component 1: G(10) + * Component 2: B(10) + * Component 3: A(2) + + * - DRM_FORMAT_ABGR8888 + - 8-bit per component RGB, with 8-bit alpha + - Plane 0: 4 components + * Component 0: R(8) + * Component 1: G(8) + * Component 2: B(8) + * Component 3: A(8) + + * - DRM_FORMAT_BGR888 + - 8-bit per component RGB + - Plane 0: 3 components + * Component 0: R(8) + * Component 1: G(8) + * Component 2: B(8) + + * - DRM_FORMAT_BGR565 + - 5/6-bit per component RGB + - Plane 0: 3 components + * Component 0: R(5) + * Component 1: G(6) + * Component 2: B(5) + + * - DRM_FORMAT_ABGR1555 + - 5-bit per component RGB, with 1-bit alpha + - Plane 0: 4 components + * Component 0: R(5) + * Component 1: G(5) + * Component 2: B(5) + * Component 3: A(1) + + * - DRM_FORMAT_VUY888 + - 8-bit per component YCbCr 444, single plane + - Plane 0: 3 components + * Component 0: Y(8) + * Component 1: Cb(8) + * Component 2: Cr(8) + + * - DRM_FORMAT_VUY101010 + - 10-bit per component YCbCr 444, single plane + - Plane 0: 3 components + * Component 0: Y(10) + * Component 1: Cb(10) + * Component 2: Cr(10) + + * - DRM_FORMAT_YUYV + - 8-bit per component YCbCr 422, single plane + - Plane 0: 3 components + * Component 0: Y(8) + * Component 1: Cb(8, 2x1 subsampled) + * Component 2: Cr(8, 2x1 subsampled) + + * - DRM_FORMAT_NV16 + - 8-bit per component YCbCr 422, two plane + - Plane 0: 1 component + * Component 0: Y(8) + Plane 1: 2 components + * Component 0: Cb(8, 2x1 subsampled) + * Component 1: Cr(8, 2x1 subsampled) + + * - DRM_FORMAT_Y210 + - 10-bit per component YCbCr 422, single plane + - Plane 0: 3 components + * Component 0: Y(10) + * Component 1: Cb(10, 2x1 subsampled) + * Component 2: Cr(10, 2x1 subsampled) + + * - DRM_FORMAT_P210 + - 10-bit per component YCbCr 422, two plane + - Plane 0: 1 component + * Component 0: Y(10) + Plane 1: 2 components + * Component 0: Cb(10, 2x1 subsampled) + * Component 1: Cr(10, 2x1 subsampled) + + * - DRM_FORMAT_YUV420_8BIT + - 8-bit per component YCbCr 420, single plane + - Plane 0: 3 components + * Component 0: Y(8) + * Component 1: Cb(8, 2x2 subsampled) + * Component 2: Cr(8, 2x2 subsampled) + + * - DRM_FORMAT_YUV420_10BIT + - 10-bit per component YCbCr 420, single plane + - Plane 0: 3 components + * Component 0: Y(10) + * Component 1: Cb(10, 2x2 subsampled) + * Component 2: Cr(10, 2x2 subsampled) + + * - DRM_FORMAT_NV12 + - 8-bit per component YCbCr 420, two plane + - Plane 0: 1 component + * Component 0: Y(8) + Plane 1: 2 components + * Component 0: Cb(8, 2x2 subsampled) + * Component 1: Cr(8, 2x2 subsampled) + + * - DRM_FORMAT_P010 + - 10-bit per component YCbCr 420, two plane + - Plane 0: 1 component + * Component 0: Y(10) + Plane 1: 2 components + * Component 0: Cb(10, 2x2 subsampled) + * Component 1: Cr(10, 2x2 subsampled) |
