aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation/gpu
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2019-11-27 17:45:48 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-11-27 17:45:48 -0800
commita6ed68d6468bd5a3da78a103344ded1435fed57a (patch)
treebe42a3609d7e9a2581806aab5bc1ace42f9ca992 /Documentation/gpu
parentMerge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net (diff)
parentMerge tag 'drm-next-5.5-2019-11-22' of git://people.freedesktop.org/~agd5f/linux into drm-next (diff)
downloadlinux-dev-a6ed68d6468bd5a3da78a103344ded1435fed57a.tar.xz
linux-dev-a6ed68d6468bd5a3da78a103344ded1435fed57a.zip
Merge tag 'drm-next-2019-11-27' of git://anongit.freedesktop.org/drm/drm
Pull drm updates from Dave Airlie: "Lots of stuff in here, though it hasn't been too insane this merge apart from dealing with the security fun. uapi: - export different colorspace properties on DP vs HDMI - new fourcc for ARM 16x16 block format - syncobj: allow querying last submitted timeline value - DRM_FORMAT_BIG_ENDIAN defined as unsigned core: - allow using gem vma manager in ttm - connector/encoder/bridge doc fixes - allow more than 3 encoders for a connector - displayport mst suspend/resume reprobing support - vram lazy unmapping, uniform vram mm and gem vram - edid cleanups + AVI informframe bar info - displayport helpers - dpcd parser added dp_cec: - Allow a connector to be associated with a cec device ttm: - pipelining with no_gpu_wait fix - always keep BOs on the LRU sched: - allow free_job routine to sleep i915: - Block userptr from mappable GTT - i915 perf uapi versioning - OA stream dynamic reconfiguration - make context persistence optional - introduce DRM_I915_UNSTABLE Kconfig - add fake lmem testing under unstable - BT.2020 support for DP MSA - struct mutex elimination - Tigerlake display/PLL/power management improvements - Jasper Lake PCH support - refactor PMU for multiple GPUs - Icelake firmware update - Split out vga + switcheroo code amdgpu: - implement dma-buf import/export without helpers - vega20 RAS enablement - DC i2c over aux fixes - renoir GPU reset - DC HDCP support - BACO support for CI/VI asics - MSI-X support - Arcturus EEPROM support - Arcturus VCN encode support - VCN dynamic powergating on RV/RV2 amdkfd: - add navi12/14/renoir support to kfd radeon: - SI dpm fix ported from amdgpu - fix bad DMA on ppc platforms gma500: - memory leak fixes qxl: - convert to new gem mmap exynos: - build warning fix komeda: - add aclk sysfs attribute v3d: - userspace cleanup uapi change i810: - fix for underflow in dispatch ioctls ast: - refactor show_cursor mgag200: - refactor show_cursor arcgpu: - encoder finding improvements mediatek: - mipi_tx, dsi and partial crtc support for MT8183 SoC - rotation support meson: - add suspend/resume support omap: - misc refactors tegra: - DisplayPort support for Tegra 210, 186 and 194. - IOMMU-backed DMA API fixes panfrost: - fix lockdep issue - simplify devfreq integration rcar-du: - R8A774B1 SoC support - fixes for H2 ES2.0 sun4i: - vcc-dsi regulator support virtio-gpu: - vmexit vs spinlock fix - move to gem shmem helpers - handle large command buffers with cma" * tag 'drm-next-2019-11-27' of git://anongit.freedesktop.org/drm/drm: (1855 commits) drm/amdgpu: invalidate mmhub semaphore workaround in gmc9/gmc10 drm/amdgpu: initialize vm_inv_eng0_sem for gfxhub and mmhub drm/amd/amdgpu/sriov skip RLCG s/r list for arcturus VF. drm/amd/amdgpu/sriov temporarily skip ras,dtm,hdcp for arcturus VF drm/amdgpu/gfx10: re-init clear state buffer after gpu reset merge fix for "ftrace: Rework event_create_dir()" drm/amdgpu: Update Arcturus golden registers drm/amdgpu/gfx10: fix out-of-bound mqd_backup array access drm/amdgpu/gfx10: explicitly wait for cp idle after halt/unhalt Revert "drm/amd/display: enable S/G for RAVEN chip" drm/amdgpu: disable gfxoff on original raven drm/amdgpu: remove experimental flag for Navi14 drm/amdgpu: disable gfxoff when using register read interface drm/amdgpu/powerplay: properly set PP_GFXOFF_MASK (v2) drm/amdgpu: fix bad DMA from INTERRUPT_CNTL2 drm/radeon: fix bad DMA from INTERRUPT_CNTL2 drm/amd/display: Fix debugfs on MST connectors drm/amdgpu/nv: add asic func for fetching vbios from rom directly drm/amdgpu: put flush_delayed_work at first drm/amdgpu/vcn2.5: fix the enc loop with hw fini ...
Diffstat (limited to 'Documentation/gpu')
-rw-r--r--Documentation/gpu/amdgpu.rst65
-rw-r--r--Documentation/gpu/drm-kms-helpers.rst3
-rw-r--r--Documentation/gpu/drm-mm.rst11
-rw-r--r--Documentation/gpu/i915.rst82
-rw-r--r--Documentation/gpu/mcde.rst2
-rw-r--r--Documentation/gpu/todo.rst135
6 files changed, 238 insertions, 60 deletions
diff --git a/Documentation/gpu/amdgpu.rst b/Documentation/gpu/amdgpu.rst
index 5acdd1842ea2..0efede580039 100644
--- a/Documentation/gpu/amdgpu.rst
+++ b/Documentation/gpu/amdgpu.rst
@@ -79,16 +79,71 @@ AMDGPU XGMI Support
.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_xgmi.c
:internal:
-AMDGPU RAS debugfs control interface
-====================================
+AMDGPU RAS Support
+==================
+
+The AMDGPU RAS interfaces are exposed via sysfs (for informational queries) and
+debugfs (for error injection).
+
+RAS debugfs/sysfs Control and Error Injection Interfaces
+--------------------------------------------------------
.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
:doc: AMDGPU RAS debugfs control interface
+RAS Reboot Behavior for Unrecoverable Errors
+--------------------------------------------------------
+
+.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
+ :doc: AMDGPU RAS Reboot Behavior for Unrecoverable Errors
+
+RAS Error Count sysfs Interface
+-------------------------------
+
+.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
+ :doc: AMDGPU RAS sysfs Error Count Interface
+
+RAS EEPROM debugfs Interface
+----------------------------
+
+.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
+ :doc: AMDGPU RAS debugfs EEPROM table reset interface
+
+RAS VRAM Bad Pages sysfs Interface
+----------------------------------
+
+.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
+ :doc: AMDGPU RAS sysfs gpu_vram_bad_pages Interface
.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
:internal:
+Sample Code
+-----------
+Sample code for testing error injection can be found here:
+https://cgit.freedesktop.org/mesa/drm/tree/tests/amdgpu/ras_tests.c
+
+This is part of the libdrm amdgpu unit tests which cover several areas of the GPU.
+There are four sets of tests:
+
+RAS Basic Test
+
+The test verifies the RAS feature enabled status and makes sure the necessary sysfs and debugfs files
+are present.
+
+RAS Query Test
+
+This test checks the RAS availability and enablement status for each supported IP block as well as
+the error counts.
+
+RAS Inject Test
+
+This test injects errors for each IP.
+
+RAS Disable Test
+
+This test tests disabling of RAS features for each IP block.
+
GPU Power/Thermal Controls and Monitoring
=========================================
@@ -130,11 +185,11 @@ pp_od_clk_voltage
.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
:doc: pp_od_clk_voltage
-pp_dpm_sclk pp_dpm_mclk pp_dpm_pcie
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+pp_dpm_*
+~~~~~~~~
.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_pm.c
- :doc: pp_dpm_sclk pp_dpm_mclk pp_dpm_pcie
+ :doc: pp_dpm_sclk pp_dpm_mclk pp_dpm_socclk pp_dpm_fclk pp_dpm_dcefclk pp_dpm_pcie
pp_power_profile_mode
~~~~~~~~~~~~~~~~~~~~~
diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst
index 3868008db8a9..9668a7fe2408 100644
--- a/Documentation/gpu/drm-kms-helpers.rst
+++ b/Documentation/gpu/drm-kms-helpers.rst
@@ -77,9 +77,6 @@ Atomic State Reset and Initialization
Atomic State Helper Reference
-----------------------------
-.. kernel-doc:: include/drm/drm_atomic_state_helper.h
- :internal:
-
.. kernel-doc:: drivers/gpu/drm/drm_atomic_state_helper.c
:export:
diff --git a/Documentation/gpu/drm-mm.rst b/Documentation/gpu/drm-mm.rst
index b664f054c259..59619296c84b 100644
--- a/Documentation/gpu/drm-mm.rst
+++ b/Documentation/gpu/drm-mm.rst
@@ -400,16 +400,13 @@ GEM VRAM Helper Functions Reference
.. kernel-doc:: drivers/gpu/drm/drm_gem_vram_helper.c
:export:
-VRAM MM Helper Functions Reference
-----------------------------------
+GEM TTM Helper Functions Reference
+-----------------------------------
-.. kernel-doc:: drivers/gpu/drm/drm_vram_mm_helper.c
+.. kernel-doc:: drivers/gpu/drm/drm_gem_ttm_helper.c
:doc: overview
-.. kernel-doc:: include/drm/drm_vram_mm_helper.h
- :internal:
-
-.. kernel-doc:: drivers/gpu/drm/drm_vram_mm_helper.c
+.. kernel-doc:: drivers/gpu/drm/drm_gem_ttm_helper.c
:export:
VMA Offset Manager
diff --git a/Documentation/gpu/i915.rst b/Documentation/gpu/i915.rst
index 3415255ad3dc..d0947c5c4ab8 100644
--- a/Documentation/gpu/i915.rst
+++ b/Documentation/gpu/i915.rst
@@ -246,6 +246,15 @@ Display PLLs
.. kernel-doc:: drivers/gpu/drm/i915/display/intel_dpll_mgr.h
:internal:
+Display State Buffer
+--------------------
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_dsb.c
+ :doc: DSB
+
+.. kernel-doc:: drivers/gpu/drm/i915/display/intel_dsb.c
+ :internal:
+
Memory Management and Command Submission
========================================
@@ -358,15 +367,6 @@ Batchbuffer Parsing
.. kernel-doc:: drivers/gpu/drm/i915/i915_cmd_parser.c
:internal:
-Batchbuffer Pools
------------------
-
-.. kernel-doc:: drivers/gpu/drm/i915/i915_gem_batch_pool.c
- :doc: batch pool
-
-.. kernel-doc:: drivers/gpu/drm/i915/i915_gem_batch_pool.c
- :internal:
-
User Batchbuffer Execution
--------------------------
@@ -415,32 +415,53 @@ Object Tiling IOCTLs
.. kernel-doc:: drivers/gpu/drm/i915/gem/i915_gem_tiling.c
:doc: buffer object tiling
+Microcontrollers
+================
+
+Starting from gen9, three microcontrollers are available on the HW: the
+graphics microcontroller (GuC), the HEVC/H.265 microcontroller (HuC) and the
+display microcontroller (DMC). The driver is responsible for loading the
+firmwares on the microcontrollers; the GuC and HuC firmwares are transferred
+to WOPCM using the DMA engine, while the DMC firmware is written through MMIO.
+
WOPCM
-=====
+-----
WOPCM Layout
-------------
+~~~~~~~~~~~~
.. kernel-doc:: drivers/gpu/drm/i915/intel_wopcm.c
:doc: WOPCM Layout
GuC
-===
+---
-Firmware Layout
--------------------
+.. kernel-doc:: drivers/gpu/drm/i915/gt/uc/intel_guc.c
+ :doc: GuC
+
+GuC Firmware Layout
+~~~~~~~~~~~~~~~~~~~
.. kernel-doc:: drivers/gpu/drm/i915/gt/uc/intel_uc_fw_abi.h
:doc: Firmware Layout
+GuC Memory Management
+~~~~~~~~~~~~~~~~~~~~~
+
+.. kernel-doc:: drivers/gpu/drm/i915/gt/uc/intel_guc.c
+ :doc: GuC Memory Management
+.. kernel-doc:: drivers/gpu/drm/i915/gt/uc/intel_guc.c
+ :functions: intel_guc_allocate_vma
+
+
GuC-specific firmware loader
-----------------------------
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.. kernel-doc:: drivers/gpu/drm/i915/gt/uc/intel_guc_fw.c
:internal:
GuC-based command submission
-----------------------------
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.. kernel-doc:: drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
:doc: GuC-based command submission
@@ -448,11 +469,26 @@ GuC-based command submission
.. kernel-doc:: drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
:internal:
-GuC Address Space
------------------
+HuC
+---
+.. kernel-doc:: drivers/gpu/drm/i915/gt/uc/intel_huc.c
+ :doc: HuC
+.. kernel-doc:: drivers/gpu/drm/i915/gt/uc/intel_huc.c
+ :functions: intel_huc_auth
-.. kernel-doc:: drivers/gpu/drm/i915/gt/uc/intel_guc.c
- :doc: GuC Address Space
+HuC Memory Management
+~~~~~~~~~~~~~~~~~~~~~
+
+.. kernel-doc:: drivers/gpu/drm/i915/gt/uc/intel_huc.c
+ :doc: HuC Memory Management
+
+HuC Firmware Layout
+~~~~~~~~~~~~~~~~~~~
+The HuC FW layout is the same as the GuC one, see `GuC Firmware Layout`_
+
+DMC
+---
+See `CSR firmware support for DMC`_
Tracing
=======
@@ -514,9 +550,9 @@ i915 Perf Stream
This section covers the stream-semantics-agnostic structures and functions
for representing an i915 perf stream FD and associated file operations.
-.. kernel-doc:: drivers/gpu/drm/i915/i915_drv.h
+.. kernel-doc:: drivers/gpu/drm/i915/i915_perf_types.h
:functions: i915_perf_stream
-.. kernel-doc:: drivers/gpu/drm/i915/i915_drv.h
+.. kernel-doc:: drivers/gpu/drm/i915/i915_perf_types.h
:functions: i915_perf_stream_ops
.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
@@ -541,7 +577,7 @@ for representing an i915 perf stream FD and associated file operations.
i915 Perf Observation Architecture Stream
-----------------------------------------
-.. kernel-doc:: drivers/gpu/drm/i915/i915_drv.h
+.. kernel-doc:: drivers/gpu/drm/i915/i915_perf_types.h
:functions: i915_oa_ops
.. kernel-doc:: drivers/gpu/drm/i915/i915_perf.c
diff --git a/Documentation/gpu/mcde.rst b/Documentation/gpu/mcde.rst
index c69e977defda..dd43dde379e0 100644
--- a/Documentation/gpu/mcde.rst
+++ b/Documentation/gpu/mcde.rst
@@ -5,4 +5,4 @@
=======================================================
.. kernel-doc:: drivers/gpu/drm/mcde/mcde_drv.c
- :doc: ST-Ericsson MCDE DRM Driver
+ :doc: ST-Ericsson MCDE Driver
diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst
index 32787acff0a8..6792fa9b6b6b 100644
--- a/Documentation/gpu/todo.rst
+++ b/Documentation/gpu/todo.rst
@@ -7,6 +7,22 @@ TODO list
This section contains a list of smaller janitorial tasks in the kernel DRM
graphics subsystem useful as newbie projects. Or for slow rainy days.
+Difficulty
+----------
+
+To make it easier task are categorized into different levels:
+
+Starter: Good tasks to get started with the DRM subsystem.
+
+Intermediate: Tasks which need some experience with working in the DRM
+subsystem, or some specific GPU/display graphics knowledge. For debugging issue
+it's good to have the relevant hardware (or a virtual driver set up) available
+for testing.
+
+Advanced: Tricky tasks that need fairly good understanding of the DRM subsystem
+and graphics topics. Generally need the relevant hardware for development and
+testing.
+
Subsystem-wide refactorings
===========================
@@ -20,6 +36,8 @@ implementations), and then remove it.
Contact: Daniel Vetter, respective driver maintainers
+Level: Intermediate
+
Convert existing KMS drivers to atomic modesetting
--------------------------------------------------
@@ -38,6 +56,8 @@ do by directly using the new atomic helper driver callbacks.
Contact: Daniel Vetter, respective driver maintainers
+Level: Advanced
+
Clean up the clipped coordination confusion around planes
---------------------------------------------------------
@@ -50,6 +70,8 @@ helpers.
Contact: Ville Syrjälä, Daniel Vetter, driver maintainers
+Level: Advanced
+
Convert early atomic drivers to async commit helpers
----------------------------------------------------
@@ -63,6 +85,8 @@ events for atomic commits correctly. But fixing these bugs is good anyway.
Contact: Daniel Vetter, respective driver maintainers
+Level: Advanced
+
Fallout from atomic KMS
-----------------------
@@ -91,6 +115,8 @@ interfaces to fix these issues:
Contact: Daniel Vetter
+Level: Intermediate
+
Get rid of dev->struct_mutex from GEM drivers
---------------------------------------------
@@ -114,6 +140,8 @@ fine-grained per-buffer object and per-context lockings scheme. Currently only t
Contact: Daniel Vetter, respective driver maintainers
+Level: Advanced
+
Convert instances of dev_info/dev_err/dev_warn to their DRM_DEV_* equivalent
----------------------------------------------------------------------------
@@ -129,6 +157,8 @@ are better.
Contact: Sean Paul, Maintainer of the driver you plan to convert
+Level: Starter
+
Convert drivers to use simple modeset suspend/resume
----------------------------------------------------
@@ -139,6 +169,8 @@ of the atomic suspend/resume code in older atomic modeset drivers.
Contact: Maintainer of the driver you plan to convert
+Level: Intermediate
+
Convert drivers to use drm_fb_helper_fbdev_setup/teardown()
-----------------------------------------------------------
@@ -157,6 +189,8 @@ probably use drm_fb_helper_fbdev_teardown().
Contact: Maintainer of the driver you plan to convert
+Level: Intermediate
+
Clean up mmap forwarding
------------------------
@@ -166,14 +200,16 @@ There's drm_gem_prime_mmap() for this now, but still needs to be rolled out.
Contact: Daniel Vetter
+Level: Intermediate
+
Generic fbdev defio support
---------------------------
The defio support code in the fbdev core has some very specific requirements,
-which means drivers need to have a special framebuffer for fbdev. Which prevents
-us from using the generic fbdev emulation code everywhere. The main issue is
-that it uses some fields in struct page itself, which breaks shmem gem objects
-(and other things).
+which means drivers need to have a special framebuffer for fbdev. The main
+issue is that it uses some fields in struct page itself, which breaks shmem
+gem objects (and other things). To support defio, affected drivers require
+the use of a shadow buffer, which may add CPU and memory overhead.
Possible solution would be to write our own defio mmap code in the drm fbdev
emulation. It would need to fully wrap the existing mmap ops, forwarding
@@ -196,6 +232,8 @@ Might be good to also have some igt testcases for this.
Contact: Daniel Vetter, Noralf Tronnes
+Level: Advanced
+
idr_init_base()
---------------
@@ -206,6 +244,8 @@ efficient.
Contact: Daniel Vetter
+Level: Starter
+
struct drm_gem_object_funcs
---------------------------
@@ -216,6 +256,8 @@ We also need a 2nd version of the CMA define that doesn't require the
vmapping to be present (different hook for prime importing). Plus this needs to
be rolled out to all drivers using their own implementations, too.
+Level: Intermediate
+
Use DRM_MODESET_LOCK_ALL_* helpers instead of boilerplate
---------------------------------------------------------
@@ -231,6 +273,8 @@ As a reference, take a look at the conversions already completed in drm core.
Contact: Sean Paul, respective driver maintainers
+Level: Starter
+
Rename CMA helpers to DMA helpers
---------------------------------
@@ -241,6 +285,9 @@ no one knows what that means) since underneath they just use dma_alloc_coherent.
Contact: Laurent Pinchart, Daniel Vetter
+Level: Intermediate (mostly because it is a huge tasks without good partial
+milestones, not technically itself that challenging)
+
Convert direct mode.vrefresh accesses to use drm_mode_vrefresh()
----------------------------------------------------------------
@@ -259,6 +306,8 @@ drm_display_mode to avoid future use.
Contact: Sean Paul
+Level: Starter
+
Remove drm_display_mode.hsync
-----------------------------
@@ -269,6 +318,8 @@ it to use drm_mode_hsync() instead.
Contact: Sean Paul
+Level: Starter
+
drm_fb_helper tasks
-------------------
@@ -284,20 +335,24 @@ drm_fb_helper tasks
removed: drm_fb_helper_single_add_all_connectors(),
drm_fb_helper_add_one_connector() and drm_fb_helper_remove_one_connector().
-Core refactorings
-=================
+Level: Intermediate
-Clean up the DRM header mess
-----------------------------
+connector register/unregister fixes
+-----------------------------------
-The DRM subsystem originally had only one huge global header, ``drmP.h``. This
-is now split up, but many source files still include it. The remaining part of
-the cleanup work here is to replace any ``#include <drm/drmP.h>`` by only the
-headers needed (and fixing up any missing pre-declarations in the headers).
+- For most connectors it's a no-op to call drm_connector_register/unregister
+ directly from driver code, drm_dev_register/unregister take care of this
+ already. We can remove all of them.
-In the end no .c file should need to include ``drmP.h`` anymore.
+- For dp drivers it's a bit more a mess, since we need the connector to be
+ registered when calling drm_dp_aux_register. Fix this by instead calling
+ drm_dp_aux_init, and moving the actual registering into a late_register
+ callback as recommended in the kerneldoc.
-Contact: Daniel Vetter
+Level: Intermediate
+
+Core refactorings
+=================
Make panic handling work
------------------------
@@ -338,6 +393,8 @@ This is a really varied tasks with lots of little bits and pieces:
Contact: Daniel Vetter
+Level: Advanced
+
Clean up the debugfs support
----------------------------
@@ -367,6 +424,8 @@ There's a bunch of issues with it:
Contact: Daniel Vetter
+Level: Intermediate
+
KMS cleanups
------------
@@ -382,6 +441,8 @@ Some of these date from the very introduction of KMS in 2008 ...
end, for which we could add drm_*_cleanup_kfree(). And then there's the (for
historical reasons) misnamed drm_primary_helper_destroy() function.
+Level: Intermediate
+
Better Testing
==============
@@ -390,6 +451,8 @@ Enable trinity for DRM
And fix up the fallout. Should be really interesting ...
+Level: Advanced
+
Make KMS tests in i-g-t generic
-------------------------------
@@ -403,6 +466,8 @@ converting things over. For modeset tests we also first need a bit of
infrastructure to use dumb buffers for untiled buffers, to be able to run all
the non-i915 specific modeset tests.
+Level: Advanced
+
Extend virtual test driver (VKMS)
---------------------------------
@@ -412,6 +477,8 @@ fit the available time.
Contact: Daniel Vetter
+Level: See details
+
Backlight Refactoring
---------------------
@@ -425,6 +492,8 @@ Plan to fix this:
Contact: Daniel Vetter
+Level: Intermediate
+
Driver Specific
===============
@@ -438,13 +507,6 @@ See drivers/gpu/drm/amd/display/TODO for tasks.
Contact: Harry Wentland, Alex Deucher
-i915
-----
-
-- Our early/late pm callbacks could be removed in favour of using
- device_link_add to model the dependency between i915 and snd_had. See
- https://dri.freedesktop.org/docs/drm/driver-api/device_link.html
-
Bootsplash
==========
@@ -460,5 +522,36 @@ for fbdev.
Contact: Sam Ravnborg
+Level: Advanced
+
Outside DRM
===========
+
+Convert fbdev drivers to DRM
+----------------------------
+
+There are plenty of fbdev drivers for older hardware. Some hwardware has
+become obsolete, but some still provides good(-enough) framebuffers. The
+drivers that are still useful should be converted to DRM and afterwards
+removed from fbdev.
+
+Very simple fbdev drivers can best be converted by starting with a new
+DRM driver. Simple KMS helpers and SHMEM should be able to handle any
+existing hardware. The new driver's call-back functions are filled from
+existing fbdev code.
+
+More complex fbdev drivers can be refactored step-by-step into a DRM
+driver with the help of the DRM fbconv helpers. [1] These helpers provide
+the transition layer between the DRM core infrastructure and the fbdev
+driver interface. Create a new DRM driver on top of the fbconv helpers,
+copy over the fbdev driver, and hook it up to the DRM code. Examples for
+several fbdev drivers are available at [1] and a tutorial of this process
+available at [2]. The result is a primitive DRM driver that can run X11
+and Weston.
+
+ - [1] https://gitlab.freedesktop.org/tzimmermann/linux/tree/fbconv
+ - [2] https://gitlab.freedesktop.org/tzimmermann/linux/blob/fbconv/drivers/gpu/drm/drm_fbconv_helper.c
+
+Contact: Thomas Zimmermann <tzimmermann@suse.de>
+
+Level: Advanced