Commit Graph

482059 Commits

Author SHA1 Message Date
Thierry Reding
f60859522a drm: Sanitize DRM_IOCTL_MODE_CREATE_DUMB input
Some drivers treat the pitch and size fields as inputs and will use them
as minima provided by userspace so that they are only overwritten if the
minimal requirements of the driver exceed them.

This can cause strange behaviour when applications don't zero out these
fields, causing whatever was on the stack to be passed to the IOCTL. In
a typical case this would become visible as a failed allocation if the
pitch or size were unusually high. But this could also cause more subtle
bugs like overallocating dumb framebuffers.

To prevent drivers from misusing these values, make the DRM core zero
out the pitch and size fields before passing the structure to the driver
implementation.

While at it, also set the output handle field to zero for good measure,
even though it's less likely to be abused.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2014-11-13 13:27:29 +01:00
Thierry Reding
7e295a36b3 drm/rcar: gem: dumb: pitch is an output
When creating a dumb buffer object using the DRM_IOCTL_MODE_CREATE_DUMB
IOCTL, only the width, height, bpp and flags fields are inputs. The
caller is not guaranteed to zero out or set handle, pitch and size.
Drivers must not treat these values as possible inputs, otherwise they
may use uninitialized memory during the computation of the framebuffer
size.

The R-Car DU driver treats the pitch passed in from userspace as minimum
and will only overwrite it when the driver-computed pitch is larger,
allowing userspace to, intentionally or not, overallocate framebuffers.

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2014-11-13 13:27:26 +01:00
Thierry Reding
bdb2b933f2 drm/omap: gem: dumb: pitch is an output
When creating a dumb buffer object using the DRM_IOCTL_MODE_CREATE_DUMB
IOCTL, only the width, height, bpp and flags fields are inputs. The
caller is not guaranteed to zero out or set handle, pitch and size.
Drivers must not treat these values as possible inputs, otherwise they
may use uninitialized memory during the computation of the framebuffer
size.

The OMAP driver uses the pitch field passed in by userspace as a minimum
and only override it if the driver-computed pitch is larger than what
userspace provided. To prevent this from causing overallocation, fix the
minimum pitch to 0 to enforce the driver-computed pitch.

Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Acked-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2014-11-13 13:27:22 +01:00
Thierry Reding
6d1782919d drm/cma: Introduce drm_gem_cma_dumb_create_internal()
This function is similar to drm_gem_cma_dumb_create() but targetted at
kernel internal users so that they can override the pitch and size
requirements of the dumb buffer.

It is important to make this difference because the IOCTL says that the
pitch and size fields are to be considered outputs and therefore should
not be used in computations of the framebuffer size. Internal users may
still want to use this code to avoid duplication and at the same time
pass on additional, driver-specific restrictions on the pitch and size.

While at it, convert the R-Car DU driver, the single user that overrides
the pitch, to use the new internal helper.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2014-11-13 13:27:17 +01:00
Thierry Reding
d7883f8759 drm/doc: Add GEM/CMA helpers to kerneldoc
Most of the functions already have the beginnings of kerneldoc comments
but are using the wrong opening marker. Use the correct opening marker
and flesh out the comments so that they can be integrated with the DRM
DocBook document.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2014-11-13 13:27:13 +01:00
Thierry Reding
790581003a drm/doc: mm: Fix indentation
Use spaces consistently for indentation in the memory-management
section.

Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2014-11-13 13:27:11 +01:00
Thierry Reding
8bf8180feb drm/gem: Fix a few kerneldoc typos
While at it, adjust the drm_gem_handle_create() function declaration to
be more consistent with other functions in the file.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2014-11-13 13:27:08 +01:00
Thierry Reding
37d74578d8 video/hdmi: Relicense header under MIT license
OpenBSD wants to reuse this file but needs the license to be more
permissive.

Acked-by: Alban Bedel <alban.bedel@avionic-design.de>
Acked-by: Daniel Vetter <daniel.vetter@intel.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2014-11-13 10:44:42 +01:00
Thierry Reding
8446956ed2 drm/gma500: mdfld: Reuse video/mipi_display.h
The GMA500 driver redefines many constants already found in the generic
header. Replace uses of the custom defines by the standard ones and get
rid of the duplicate defininitions.

Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2014-11-13 10:44:41 +01:00
Thierry Reding
2f7633125a drm: Make drm_mode_create_tv_properties() signature consistent
The prototype and the function implementation differ in their signature.
Make them consistent and use an unsigned integer for the number of modes
while at it.

Signed-off-by: Thierry Reding <treding@nvidia.com>
2014-11-13 10:43:51 +01:00
Thierry Reding
a9e3c90c9f drm: Implement drm_get_pci_dev() dummy for !PCI
Implementing a dummy of this function allows drivers that use it to be
built on platforms that don't have PCI. This can happen for example if
the nouveau driver is built on Tegra without PCI enabled (or on 64-bit
ARM where PCI is not yet implemented).

Signed-off-by: Thierry Reding <treding@nvidia.com>
2014-11-13 10:43:50 +01:00
Thierry Reding
34eab43ed2 drm/prime: Use unsigned type for number of pages
The number of pages can never be negative, so an unsigned type is
enough. This also matches the type of the n_pages argument of the
sg_alloc_table_from_pages() function.

Signed-off-by: Thierry Reding <treding@nvidia.com>
2014-11-13 10:43:50 +01:00
Thierry Reding
c6a843256a drm/gem: Fix typo in kerneldoc
The function being documented is drm_gem_object_handle_free(), not
drm_gem_object_free().

Signed-off-by: Thierry Reding <treding@nvidia.com>
2014-11-13 10:43:49 +01:00
Thierry Reding
12e6cecd55 drm: Use const data when creating blob properties
Creating a blob property will always copy the input data so the data
that is passed in can be const.

Signed-off-by: Thierry Reding <treding@nvidia.com>
2014-11-13 10:43:49 +01:00
Thierry Reding
ecbbe59bbb drm: Use size_t for blob property sizes
size_t is the standard type when dealing with sizes of all kinds. Use it
consistently when instantiating DRM blob properties.

Signed-off-by: Thierry Reding <treding@nvidia.com>
2014-11-13 10:43:48 +01:00
Dave Airlie
7fd36c0bae Merge branch 'drm-next-3.19' of git://people.freedesktop.org/~agd5f/linux into drm-next
Radeon patches for 3.19.  Christian has a number of GPUVM improvements
slated as well, but I'd like to wait until he gets back to work next week
to pull those in. Highlights of this pull:
- ttm performance improvements
- CI dpm fixes

* 'drm-next-3.19' of git://people.freedesktop.org/~agd5f/linux: (26 commits)
  drm/radeon/si/ci: make u8 static arrays constant
  drm/radeon: set power control in ci dpm enable
  drm/radeon: powertune fixes for hawaii
  drm/radeon: fix dpm mc init for certain hawaii boards
  drm/radeon: set bootup pcie level to max for ci dpm
  drm/radeon: fix default dpm state setup
  drm/radeon: workaround a hw bug in bonaire pcie dpm
  drm/radeon: fix mclk vddc configuration for cards for hawaii
  drm/radeon: fix sclk DS enablement
  drm/radeon: fix activity settings for sclk and mclk for CI
  drm/radeon: improve mclk param calcuations for ci dpm
  drm/radeon: fix dram timing for certain hawaii boards
  drm/radeon: switch force state commands for CI
  drm/radeon: fix for memory training on bonaire 0x6649
  drm/radeon/ci: handle gpio controlled dpm features properly
  drm/radeon: store the gpio shift as well
  drm/radeon: export radeon_atombios_lookup_gpio
  drm/radeon: fix typo in CI dpm disable
  drm/radeon: rework CI dpm thermal setup
  drm/radeon: rework SI dpm thermal setup
  ...
2014-11-13 09:06:41 +10:00
Dave Airlie
c81b99423b drm/radeon/si/ci: make u8 static arrays constant
These two arrays don't change, just make them constant,
reduces data segment by a few bytes.

Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2014-11-12 11:56:46 -05:00
Alex Deucher
b94b95e7e3 drm/radeon: set power control in ci dpm enable
Necessary for poper operation.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2014-11-12 11:56:46 -05:00
Alex Deucher
542b379b55 drm/radeon: powertune fixes for hawaii
- bapm is not available on hawaii
- update pt defaults

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2014-11-12 11:56:45 -05:00
Alex Deucher
90b2fee35c drm/radeon: fix dpm mc init for certain hawaii boards
Needs special overrides for certain vram configurations.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2014-11-12 11:56:44 -05:00
Alex Deucher
4e21518c3d drm/radeon: set bootup pcie level to max for ci dpm
Avoids problems when re-loading the driver.  Does not
affect power saving when dpm is enabled.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2014-11-12 11:56:44 -05:00
Alex Deucher
b6b41cf3b6 drm/radeon: fix default dpm state setup
Only enable the first levels for mclk and sclk.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2014-11-12 11:56:43 -05:00
Alex Deucher
36654dd4b9 drm/radeon: workaround a hw bug in bonaire pcie dpm
Some boards get stuck in pcie x1 otherwise.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2014-11-12 11:56:42 -05:00
Alex Deucher
127e056e2a drm/radeon: fix mclk vddc configuration for cards for hawaii
Need to use vddc0 for vdcc1 for certain hawaii configurations.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2014-11-12 11:56:42 -05:00
Alex Deucher
489ba72c1e drm/radeon: fix sclk DS enablement
Only enable it for levels 0 and 1.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2014-11-12 11:56:41 -05:00
Alex Deucher
d3052b8ce8 drm/radeon: fix activity settings for sclk and mclk for CI
Only need to be enabled on the first level.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2014-11-12 11:56:40 -05:00
Alex Deucher
c0392f8f09 drm/radeon: improve mclk param calcuations for ci dpm
Properly take into account the post divider.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2014-11-12 11:56:40 -05:00
Alex Deucher
21b8a36904 drm/radeon: fix dram timing for certain hawaii boards
Certain memory configurations need a fix.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2014-11-12 11:56:39 -05:00
Alex Deucher
1c52279f57 drm/radeon: switch force state commands for CI
Use the preferred SMC commands for forcing state on CI.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2014-11-12 11:56:38 -05:00
Alex Deucher
9feb3dda5c drm/radeon: fix for memory training on bonaire 0x6649
Workaround for memory link training on certain variants
of 0x6649.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2014-11-12 11:56:38 -05:00
Alex Deucher
34fc0b58d9 drm/radeon/ci: handle gpio controlled dpm features properly
Certain feature enablement depends on entries in the atom
gpio pin table.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2014-11-12 11:56:37 -05:00
Alex Deucher
727b3d25be drm/radeon: store the gpio shift as well
We need this in the dpm code.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2014-11-12 11:56:36 -05:00
Alex Deucher
09e619c0c6 drm/radeon: export radeon_atombios_lookup_gpio
We need it for dpm.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2014-11-12 11:56:36 -05:00
Alex Deucher
129acb7c0b drm/radeon: fix typo in CI dpm disable
Need to disable DS, not enable it when disabling dpm.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
2014-11-12 11:56:35 -05:00
Alex Deucher
1955f107a7 drm/radeon: rework CI dpm thermal setup
In preparation for fan control.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2014-11-12 11:56:35 -05:00
Alex Deucher
2271e2e2a2 drm/radeon: rework SI dpm thermal setup
In preparation for fan control.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2014-11-12 11:56:34 -05:00
Alex Deucher
9b92d1ec62 drm/radeon/dpm: grab fan info from vbios
Required for fan control support.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2014-11-12 11:56:33 -05:00
Michel Dänzer
507d0ca71b drm/ttm: Use only DRM_MM_SEARCH_BELOW for TTM_PL_FLAG_TOPDOWN
DRM_MM_SEARCH_BEST gets the smallest hole which can fit the BO. That seems
against the idea of TTM_PL_FLAG_TOPDOWN:

* The smallest hole may be in the overall bottom of the area
* If the hole isn't much larger than the BO, it doesn't make much
  difference whether the BO is placed at the bottom or at the top of the
  hole

Reviewed-by: Lauri Kasanen <cand@gmx.com>
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2014-11-12 11:56:33 -05:00
Michel Dänzer
c165812cbf drm/ttm: Add DRM_MM_SEARCH_BELOW for TTM_PL_FLAG_TOPDOWN
If the BO should be placed at the top of the area, we should start looking
for holes from the top.

Reviewed-by: Lauri Kasanen <cand@gmx.com>
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2014-11-12 11:56:32 -05:00
Michel Dänzer
a8b5ebe6b5 drm/radeon: Set TTM_PL_FLAG_TOPDOWN also for RADEON_GEM_CPU_ACCESS BOs
I wasn't sure if TTM_PL_FLAG_TOPDOWN works correctly with non-0 lpfn, but
AFAICT it does.

Reviewed-by: Lauri Kasanen <cand@gmx.com>
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2014-11-12 11:56:31 -05:00
Michel Dänzer
2a85aedd11 drm/radeon: Try evicting from CPU accessible to inaccessible VRAM first
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2014-11-12 11:29:10 -05:00
Michel Dänzer
c9da4a4b38 drm/radeon: Try placing NO_CPU_ACCESS BOs outside of CPU accessible VRAM
This avoids them getting in the way of BOs which might be accessed by
the CPU. They can still go to the CPU accessible part of VRAM though if
there's no space outside of it.

Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2014-11-12 11:29:10 -05:00
Ander Conselvan de Oliveira
f354d733f6 drm/i915: Plug memory leak in intel_shared_dpll_start_config()
The cleanup path would reset pll->new_config to NULL but wouldn't free
the allocated memory.

Signed-off-by: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2014-11-12 10:53:04 +01:00
Daniel Vetter
fcf93f6948 drm: More specific locking for get* ioctls
Motivated by the per-plane locking I've gone through all the get*
ioctls and reduced the locking to the bare minimum required.

v2: Rebase and make it compile ...

v3: Review from Sean:
- Simplify return handling in getplane_res.
- Add a comment to getplane_res that the plane list is invariant and
  can be walked locklessly.

v4: Actually git add.

Cc: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2014-11-12 17:56:34 +10:00
Daniel Vetter
4d02e2de0e drm: Per-plane locking
Turned out to be much simpler on top of my latest atomic stuff than
what I've feared. Some details:

- Drop the modeset_lock_all snakeoil in drm_plane_init. Same
  justification as for the equivalent change in drm_crtc_init done in

	commit d0fa1af40e
	Author: Daniel Vetter <daniel.vetter@ffwll.ch>
	Date:   Mon Sep 8 09:02:49 2014 +0200

	    drm: Drop modeset locking from crtc init function

  Without these the drm_modeset_lock_init would fall over the exact
  same way.

- Since the atomic core code wraps the locking switching it to
  per-plane locks was a one-line change.

- For the legacy ioctls add a plane argument to the locking helper so
  that we can grab the right plane lock (cursor or primary). Since the
  universal cursor plane might not be there, or someone really crazy
  might forgoe the primary plane even accept NULL.

- Add some locking WARN_ON to the atomic helpers for good paranoid
  measure and to check that it all works out.

Tested on my exynos atomic hackfest with full lockdep checks and ww
backoff injection.

v2: I've forgotten about the load-detect code in i915.

v3: Thierry reported that in latest 3.18-rc vmwgfx doesn't compile any
more due to

commit 21e88620aa
Author: Rob Clark <robdclark@gmail.com>
Date:   Thu Oct 30 13:39:04 2014 -0400

    drm/vmwgfx: fix lock breakage

Rebased and fix this up.

Cc: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2014-11-12 17:56:12 +10:00
Rob Clark
5ee3229c87 drm: export atomic wait_for_vblanks helper (v2)
v1: original
v2: danvet's kerneldoc nitpicks

Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2014-11-12 17:55:44 +10:00
Dave Airlie
51b44eb17b Linux 3.18-rc4
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Merge tag 'v3.18-rc4' into drm-next

backmerge to get vmwgfx locking changes into next as the
conflict with per-plane locking.
2014-11-12 17:53:30 +10:00
Daniel Vetter
eb84f976c8 Merge remote-tracking branch 'airlied/drm-next' into HEAD
Backmerge drm-next so that I can keep merging patches. Specifically I
want:
- atomic stuff, yay!
- eld parsing patch from Jani.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
2014-11-10 10:55:35 +01:00
Dave Airlie
cc7096fb6d drm/mode: document path property and function to set it. (v1.1)
These two didn't get documented properly, do so.

Pointed out by Daniel.

v1.1: add missing boilerplate (Daniel)

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2014-11-10 10:21:14 +10:00
Dave Airlie
122387a53e Merge tag 'topic/atomic-helpers-2014-11-09' of git://anongit.freedesktop.org/drm-intel into drm-next
So here's my atomic series, finally all debugged&reviewed. Sean Paul has
done a full detailed pass over it all, and a lot of other people have
commented and provided feedback on some parts. Rob Clark also converted
msm over the w/e and seems happy. The only small thing is that Rob wants
to export the wait_for_vblank, which imo makes sense. Since there's other
stuff still to do I think we should apply Rob's patch (once it has grown
appropriate kerneldoc) later on top of this.

This is just the core<->driver interface plus a big pile of helpers. Short
recap of the main ideas:

- There are essentially three helper libraries in this patch set:

  * Transitional helpers to use the new plane callbacks for legacy plane
    updates and in the crtc helper's ->mode_set callback. These helpers are
    only temporarily used to convert drivers to atomic, but they allow a
    nice separation between changing the driver backend and switching to
    the atomic commit logic.

  * Legacy helpers to implement all the legacy driver entry points
    (page_flip, set_config, plane vfuncs) on top of the new atomic driver
    interface. These are completely driver agnostic. The reason for having
    the legacy support as helpers is that drivers can switch step-by-step.
    And they could e.g. even keep the legacy page_flip code around for some
    old platforms where converting to full-blown atomic isn't worth it.

  * Atomic helpers which implement the various new ->atomic_* driver
    interfaces in terms of the revised crtc helper and new plane helper
    hooks.

- The revised crtc helper implemenation essentially implements all the
  lessons learned in the i915 modeset rework (when using the atomic helpers
  only):

  * Enable/disable sequence for a given config are always the same and
    callbacks are always called in the same order. This contrast starkly
    with the crtc helpers, where the sequence of operations is heavily
    dependent on the previous config.

    One corollary of this is that if the configuration of a crtc only
    partially changes (e.g. a connector moves in a cloned config) the
    helper code will still disable/enable the full display pipeline. This
    is the only way to ensure that the enable/disable sequence is always
    the same.

  * It won't call disable or enable hooks more than once any more because
    it lost track of state, thanks to the atomic state tracking. And if
    drivers implement the ->reset hook properly (by either resetting the hw
    or reading out the hw state into the atomic structures) this even
    extends to the hardware state. So no more disable-me-harder kind of
    nonsense.

  * The only thing missing is the hw state readout/cross-check support, but
    if drivers have hw state readout support in their ->reset handlers it's
    simple to extend that to cross-check the hw state.

  * The crtc->mode_set callback is gone and its replacement only sets crtc
    timings and no longer updates the primary plane state. This way we can
    finally implement primary planes properly.

- The new plane helpers should be suitable enough for pretty much
  everything, and a perfect fit for hardware with GO bits. Even if they
  don't fit the atomic helper library is rather flexible and exports all
  the functions for the individual steps to drivers. So drivers can pick
  what matches and implement their own magic for everything else.

- A big difference compared to all previous atomic series is that this one
  doesn't implement async commit in a generic way. Imo driver requirements
  for that are too diverse to create anything reasonable sane which would
  actually work on a reasonable amount of different drivers. Also, we've
  never had a helper library for page_flips even, so it's really hard to
  know what might work and what's stupid without a bit of experience in the form
  of a few driver implementations.

  I think with the current flexibility for drivers to pick individual
  stages and existing helpers like drm_flip_queue it's rather easy though
  to implement proper async commit.

- There's a few other differences of minor importance to earlier atomic
  series:

  * Common/generic properties are parsed in the callers/core and not in
    drivers, and passed to drivers by directly setting the right members in
    atomic state structures. That greatly simplifies all the transitional
    and legacy helpers an removes a lot of boilerplate code.

  * There's no crazy trylock mode used for the async commit since these
    helpers don't do async commit. A simple ordered flip queue of atomic
    state updates should be sufficient for preventing concurrent hw access
    anyway, as long as synchronous updates stall correctly with e.g.
    flush_work_queue or similar function. Abusing locks to enforce ordering
    isn't a good idea imo anyway.

  * These helpers reuse the existing ->mode_fixup hooks in the atomic_check
    callback. Which means that drivers need to adapat and move a lot less code
    into their atomic_check callbacks.

Now this isn't everything needed in the drm core and helpers for full
atomic support. But it's enough to start with converting drivers, and
except for actually testing multiplane and multicrtc updates also enough to
implement full atomic updates. Still missing are:

- Per-plane locking. Since these helpers here encapsulate the locking
  completely this should be fairly easy to implement.

- fbdev support for atomic_check/commit, so that multi-pipe finally works
  sanely in fbcon.

- Adding and decoding shared/core properties. That just needs to be rebased
  from Rob's latest patch series, with minor adjustments so that the
  decoding happens in the core instead of in drivers.

- Actually adding the atomic ioctl. Again just rebasing Rob's latest patch
  should be all that's needed.

- Resolving how to deal with DPMS in atomic. Atomic is a good excuse to fix up
  the crazy semantics dpms currently has. I'm floating an RFC about this topic
  already.

- Finally I couldn't test connector/encoder stealing properly since my test
  vehicle here doesn't allow a connector on different crtcs. So drivers
  which support this might see some surprises in that area. There is no semantic
  change though in how encoder stealing and assignment works (or at least no
  intended one), so I think the risk is minimal.

As just mentioned I've done a fake conversion of an existing driver using
crtc helpers to debug the helper code and validate the smooth transition
approach. And that smooth transition was the really big motivation for
this. It seems to actually work and consists of 3 phases:

Phase 1: Rework driver backend for crtc/plane helpers

The requirement here is that universal plane support is already implement. If
universal plane support isn't implement yet it might be better though to just do
it as part of this phase, directly using the new plane helpers. There are two
big things to do:

- Split up the existing ->update/disable_plane hooks into check/commit
  hooks and extract the crtc-wide prep/flush parts (like setting/clearing
  GO bits).

- The other big change is to split the crtc->mode_set hook into the plane
  update (done using the plane helpers) and the crtc setup in a new
  ->mode_set_nofb hook.

When phase 1 is complete the driver implements all the new callbacks which
push the software state into hardware, but still using all the legacy entry
points and crtc helpers. The transitional helpers serve as impendance
mismatch here.

Phase 2: Rework state handling

This consists of rolling out the state handling helpers for planes, crtcs
and connectors and reviewing all ->mode_fixup and similar hooks to make
sure they don't depend upon implicit global state which might change in the
atomic world. Any such code must be moved into ->atomic_check functions which
just rely on the free-standing atomic state update structures.

This phase also adds a few small pieces of fixup code to make sure the
atomic state doesn't get out of sync in the legacy driver callbacks.

Phase 3: Roll out atomic support

Now it's just about replacing vfuncs with the ones provided by the helper
and filling out the small missing pieces (like atomic_check logic or async
commit support needed for page_flips). Due to the prep work in phase 1 no
changes to the driver backend functions should be required, and because of
the prep work in phase 2 atomic implementations can be rolled out
step-by-step. So if async commit ins't implemented yet page_flip can be
implemented with the legacy functions without wreaking havoc in the other
operations.

* tag 'topic/atomic-helpers-2014-11-09' of git://anongit.freedesktop.org/drm-intel:
  drm/atomic: Refcounting for plane_state->fb
  drm: Docbook integration and over sections for all the new helpers
  drm/atomic-helpers: functions for state duplicate/destroy/reset
  drm/atomic-helper: implement ->page_flip
  drm/atomic-helpers: document how to implement async commit
  drm/atomic: Integrate fence support
  drm/atomic-helper: implementatations for legacy interfaces
  drm: Atomic crtc/connector updates using crtc/plane helper interfaces
  drm/crtc-helper: Transitional functions using atomic plane helpers
  drm/plane-helper: transitional atomic plane helpers
  drm: Add atomic/plane helpers
  drm: Global atomic state handling
  drm: Add atomic driver interface definitions for objects
  drm/modeset_lock: document trylock_only in kerneldoc
  drm: fixup kerneldoc in drm_crtc.h
  drm: Pull drm_crtc.h into the kerneldoc template
  drm: Move drm_crtc_init from drm_crtc.h to drm_plane_helper.h
2014-11-10 09:59:16 +10:00