[PATCH 00/19] wire acquire ctx through legacy modeset paths

[Daniel Vetter]

Hi all,

This is something I kinda had on my todo list ever since atomic landed. The
legacy_backoff() hack really doesn't work if you need to acquire additional
locks, which does restrict drivers in how they handle and protect legacy paths,
and kinda forces us to be overzealous with taking locks for legacy paths, just
in case.

This patch set here fixes this, with 2 huge exceptions:
- get/set_property calls aren't fixed. The locking in there is a mess and needs
  some serious attention. My goal would be that for atomic we take no lock at
  all, and entirely rely upon the magic of drm_modeset_lock and atomic to just
  grab the minimal set required to update a property.

- fbdev emulation helpers. It abused the modeset_lock_all bkl as its own lock,
  which prevents us from pushing it down just around the (atomic) modeset calls,
  and hence from switching over to handling the acquire context in an explicit
  fashion. Thierry started to fix this with the addition of proper locking for
  fbdev emulation, but it needs a pile more work.

Survived light testing with full ww mutex debugging, I'll rely on CI to catch
the remaining mixups :-)

Cheers, Daniel

Daniel Vetter (19):
  drm: Wire up proper acquire ctx for plane functions
  drm: Add acquire ctx parameter to ->update_plane
  drm: drm_plane_force_disable is not for atomic drivers
  drm: Add acquire ctx parameter to ->plane_disable
  drm/atomic-helper: remove backoff hack from disable/update_plane
  drm/vmwgfx: Drop the cursor locking hack
  drm/tegra: Don't use modeset_lock_crtc
  drm/tilcdc: Drop calls to modeset_lock_crtc
  drm: Make drm_modeset_lock_crtc internal
  drm: Roll out acquire context for the page_flip ioctl
  drm: Add acquire ctx parameter to ->page_flip(_target)
  drm/atomic-helper: remove backoff hack from page_flip
  drm: simplify the locking in the GETCRTC ioctl
  drm: Remove drm_modeset_(un)lock_crtc
  drm: Remove drm_modeset_legacy_acquire_ctx and crtc->acquire_ctx
  drm: Restrict drm_mode_set_config_internal to non-atomic drivers
  drm: Add explicit acquire ctx handling around ->set_config
  drm: Add acquire ctx parameter to ->set_config
  drm/atomic-helper: Remove the backoff hack from set_config

 drivers/gpu/drm/amd/amdgpu/amdgpu_display.c |   8 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h    |   6 +-
 drivers/gpu/drm/armada/armada_crtc.c        |   3 +-
 drivers/gpu/drm/armada/armada_overlay.c     |   6 +-
 drivers/gpu/drm/bochs/bochs_kms.c           |   3 +-
 drivers/gpu/drm/drm_atomic.c                |  14 ---
 drivers/gpu/drm/drm_atomic_helper.c         | 132 +++++-----------------------
 drivers/gpu/drm/drm_crtc.c                  |  61 ++++++++-----
 drivers/gpu/drm/drm_crtc_helper.c           |   4 +-
 drivers/gpu/drm/drm_modeset_lock.c          | 102 ---------------------
 drivers/gpu/drm/drm_plane.c                 |  87 ++++++++++++++----
 drivers/gpu/drm/drm_plane_helper.c          |  11 ++-
 drivers/gpu/drm/gma500/gma_display.c        |   7 +-
 drivers/gpu/drm/gma500/gma_display.h        |   3 +-
 drivers/gpu/drm/i915/intel_display.c        |   9 +-
 drivers/gpu/drm/i915/intel_pipe_crc.c       |   2 +-
 drivers/gpu/drm/msm/mdp/mdp5/mdp5_plane.c   |   8 +-
 drivers/gpu/drm/nouveau/dispnv04/crtc.c     |   7 +-
 drivers/gpu/drm/nouveau/dispnv04/overlay.c  |  18 ++--
 drivers/gpu/drm/nouveau/nouveau_display.c   |   3 +-
 drivers/gpu/drm/nouveau/nouveau_display.h   |   4 +-
 drivers/gpu/drm/radeon/radeon_display.c     |   8 +-
 drivers/gpu/drm/shmobile/shmob_drm_crtc.c   |   3 +-
 drivers/gpu/drm/shmobile/shmob_drm_plane.c  |   8 +-
 drivers/gpu/drm/tegra/dc.c                  |   8 +-
 drivers/gpu/drm/tilcdc/tilcdc_crtc.c        |  12 +--
 drivers/gpu/drm/udl/udl_modeset.c           |   3 +-
 drivers/gpu/drm/vc4/vc4_crtc.c              |   5 +-
 drivers/gpu/drm/vc4/vc4_plane.c             |   6 +-
 drivers/gpu/drm/vmwgfx/vmwgfx_kms.c         |  25 ------
 drivers/gpu/drm/vmwgfx/vmwgfx_ldu.c         |   3 +-
 drivers/gpu/drm/vmwgfx/vmwgfx_scrn.c        |   6 +-
 drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c        |   6 +-
 include/drm/drm_atomic_helper.h             |  15 ++--
 include/drm/drm_crtc.h                      |  18 ++--
 include/drm/drm_crtc_helper.h               |   3 +-
 include/drm/drm_modeset_lock.h              |   5 --
 include/drm/drm_plane.h                     |   7 +-
 include/drm/drm_plane_helper.h              |   6 +-
 39 files changed, 265 insertions(+), 380 deletions(-)

-- 
2.11.0