git.openwrt.org Git - openwrt/staging/nbd.git/blob

   1 From 268e65023226cc59363dd9c9d9ad56a11588f4c3 Mon Sep 17 00:00:00 2001
   2 From: Daniel Vetter <daniel.vetter@ffwll.ch>
   3 Date: Fri, 23 Oct 2020 14:39:23 +0200
   4 Subject: [PATCH 0025/1085] drm/atomic-helpers: remove legacy_cursor_update
   5  hacks
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   7 Content-Type: text/plain; charset=UTF-8
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   9
  10 The stuff never really worked, and leads to lots of fun because it
  11 out-of-order frees atomic states. Which upsets KASAN, among other
  12 things.
  13
  14 For async updates we now have a more solid solution with the
  15 ->atomic_async_check and ->atomic_async_commit hooks. Support for that
  16 for msm and vc4 landed. nouveau and i915 have their own commit
  17 routines, doing something similar.
  18
  19 For everyone else it's probably better to remove the use-after-free
  20 bug, and encourage folks to use the async support instead. The
  21 affected drivers which register a legacy cursor plane and don't either
  22 use the new async stuff or their own commit routine are: amdgpu,
  23 atmel, mediatek, qxl, rockchip, sti, sun4i, tegra, virtio, and vmwgfx.
  24
  25 Inspired by an amdgpu bug report.
  26
  27 v2: Drop RFC, I think with amdgpu converted over to use
  28 atomic_async_check/commit done in
  29
  30 commit 674e78acae0dfb4beb56132e41cbae5b60f7d662
  31 Author: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
  32 Date:   Wed Dec 5 14:59:07 2018 -0500
  33
  34     drm/amd/display: Add fast path for cursor plane updates
  35
  36 we don't have any driver anymore where we have userspace expecting
  37 solid legacy cursor support _and_ they are using the atomic helpers in
  38 their fully glory. So we can retire this.
  39
  40 v3: Paper over msm and i915 regression. The complete_all is the only
  41 thing missing afaict.
  42
  43 v4: Rebased on recent kernel, added extra link for vc4 bug.
  44
  45 Link: https://bugzilla.kernel.org/show_bug.cgi?id=199425
  46 Link: https://lore.kernel.org/all/20220221134155.125447-9-maxime@cerno.tech/
  47 Cc: mikita.lipski@amd.com
  48 Cc: Michel Dänzer <michel@daenzer.net>
  49 Cc: harry.wentland@amd.com
  50 Cc: Rob Clark <robdclark@gmail.com>
  51 Cc: "Kazlauskas, Nicholas" <nicholas.kazlauskas@amd.com>
  52 Tested-by: Maxime Ripard <maxime@cerno.tech>
  53 Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
  54 Signed-off-by: Maxime Ripard <maxime@cerno.tech>
  55 ---
  56  drivers/gpu/drm/drm_atomic_helper.c          | 13 -------------
  57  drivers/gpu/drm/i915/display/intel_display.c | 13 +++++++++++++
  58  drivers/gpu/drm/msm/msm_atomic.c             |  2 ++
  59  3 files changed, 15 insertions(+), 13 deletions(-)
  60
  61 --- a/drivers/gpu/drm/drm_atomic_helper.c
  62 +++ b/drivers/gpu/drm/drm_atomic_helper.c
  63 @@ -1653,13 +1653,6 @@ drm_atomic_helper_wait_for_vblanks(struc
  64         int i, ret;
  65         unsigned int crtc_mask = 0;
  66
  67 -        /*
  68 -         * Legacy cursor ioctls are completely unsynced, and userspace
  69 -         * relies on that (by doing tons of cursor updates).
  70 -         */
  71 -       if (old_state->legacy_cursor_update)
  72 -               return;
  73 -
  74         for_each_oldnew_crtc_in_state(old_state, crtc, old_crtc_state, new_crtc_state, i) {
  75                 if (!new_crtc_state->active)
  76                         continue;
  77 @@ -2309,12 +2302,6 @@ int drm_atomic_helper_setup_commit(struc
  78                         complete_all(&commit->flip_done);
  79                         continue;
  80                 }
  81 -
  82 -               /* Legacy cursor updates are fully unsynced. */
  83 -               if (state->legacy_cursor_update) {
  84 -                       complete_all(&commit->flip_done);
  85 -                       continue;
  86 -               }
  87
  88                 if (!new_crtc_state->event) {
  89                         commit->event = kzalloc(sizeof(*commit->event),
  90 --- a/drivers/gpu/drm/i915/display/intel_display.c
  91 +++ b/drivers/gpu/drm/i915/display/intel_display.c
  92 @@ -7280,6 +7280,19 @@ int intel_atomic_commit(struct drm_devic
  93                                 state->base.legacy_cursor_update = false;
  94         }
  95
  96 +       /*
  97 +        * FIXME: Cut over to (async) commit helpers instead of hand-rolling
  98 +        * everything.
  99 +        */
 100 +       if (state->base.legacy_cursor_update) {
 101 +               struct intel_crtc_state *new_crtc_state;
 102 +               struct intel_crtc *crtc;
 103 +               int i;
 104 +
 105 +               for_each_new_intel_crtc_in_state(state, crtc, new_crtc_state, i)
 106 +                       complete_all(&new_crtc_state->uapi.commit->flip_done);
 107 +       }
 108 +
 109         ret = intel_atomic_prepare_commit(state);
 110         if (ret) {
 111                 drm_dbg_atomic(&dev_priv->drm,
 112 --- a/drivers/gpu/drm/msm/msm_atomic.c
 113 +++ b/drivers/gpu/drm/msm/msm_atomic.c
 114 @@ -242,6 +242,8 @@ void msm_atomic_commit_tail(struct drm_a
 115                 /* async updates are limited to single-crtc updates: */
 116                 WARN_ON(crtc_mask != drm_crtc_mask(async_crtc));
 117
 118 +               complete_all(&async_crtc->state->commit->flip_done);
 119 +
 120                 /*
 121                  * Start timer if we don't already have an update pending
 122                  * on this crtc: