queue-5.1/drm-rockchip-fix-fb-references-in-async-update.patch

   1 From d985a3533274ef7dd1ccb25cb05a72259b25268f Mon Sep 17 00:00:00 2001
   2 From: Helen Koike <helen.koike@collabora.com>
   3 Date: Mon, 3 Jun 2019 13:56:06 -0300
   4 Subject: drm/rockchip: fix fb references in async update
   5
   6 From: Helen Koike <helen.koike@collabora.com>
   7
   8 commit d985a3533274ef7dd1ccb25cb05a72259b25268f upstream.
   9
  10 In the case of async update, modifications are done in place, i.e. in the
  11 current plane state, so the new_state is prepared and the new_state is
  12 cleaned up (instead of the old_state, unlike what happens in a
  13 normal sync update).
  14 To cleanup the old_fb properly, it needs to be placed in the new_state
  15 in the end of async_update, so cleanup call will unreference the old_fb
  16 correctly.
  17
  18 Also, the previous code had a:
  19
  20         plane_state = plane->funcs->atomic_duplicate_state(plane);
  21         ...
  22         swap(plane_state, plane->state);
  23
  24         if (plane->state->fb && plane->state->fb != new_state->fb) {
  25         ...
  26         }
  27
  28 Which was wrong, as the fb were just assigned to be equal, so this if
  29 statement nevers evaluates to true.
  30
  31 Another details is that the function drm_crtc_vblank_get() can only be
  32 called when vop->is_enabled is true, otherwise it has no effect and
  33 trows a WARN_ON().
  34
  35 Calling drm_atomic_set_fb_for_plane() (which get a referent of the new
  36 fb and pus the old fb) is not required, as it is taken care by
  37 drm_mode_cursor_universal() when calling
  38 drm_atomic_helper_update_plane().
  39
  40 Fixes: 15609559a834 ("drm/rockchip: update cursors asynchronously through atomic.")
  41 Cc: <stable@vger.kernel.org> # v4.20+
  42 Signed-off-by: Helen Koike <helen.koike@collabora.com>
  43 Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
  44 Link: https://patchwork.freedesktop.org/patch/msgid/20190603165610.24614-2-helen.koike@collabora.com
  45 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  46
  47 ---
  48  drivers/gpu/drm/rockchip/rockchip_drm_vop.c |   49 ++++++++++++++--------------
  49  1 file changed, 25 insertions(+), 24 deletions(-)
  50
  51 --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
  52 +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
  53 @@ -924,29 +924,17 @@ static void vop_plane_atomic_async_updat
  54                                           struct drm_plane_state *new_state)
  55  {
  56         struct vop *vop = to_vop(plane->state->crtc);
  57 -       struct drm_plane_state *plane_state;
  58 +       struct drm_framebuffer *old_fb = plane->state->fb;
  59
  60 -       plane_state = plane->funcs->atomic_duplicate_state(plane);
  61 -       plane_state->crtc_x = new_state->crtc_x;
  62 -       plane_state->crtc_y = new_state->crtc_y;
  63 -       plane_state->crtc_h = new_state->crtc_h;
  64 -       plane_state->crtc_w = new_state->crtc_w;
  65 -       plane_state->src_x = new_state->src_x;
  66 -       plane_state->src_y = new_state->src_y;
  67 -       plane_state->src_h = new_state->src_h;
  68 -       plane_state->src_w = new_state->src_w;
  69 -
  70 -       if (plane_state->fb != new_state->fb)
  71 -               drm_atomic_set_fb_for_plane(plane_state, new_state->fb);
  72 -
  73 -       swap(plane_state, plane->state);
  74 -
  75 -       if (plane->state->fb && plane->state->fb != new_state->fb) {
  76 -               drm_framebuffer_get(plane->state->fb);
  77 -               WARN_ON(drm_crtc_vblank_get(plane->state->crtc) != 0);
  78 -               drm_flip_work_queue(&vop->fb_unref_work, plane->state->fb);
  79 -               set_bit(VOP_PENDING_FB_UNREF, &vop->pending);
  80 -       }
  81 +       plane->state->crtc_x = new_state->crtc_x;
  82 +       plane->state->crtc_y = new_state->crtc_y;
  83 +       plane->state->crtc_h = new_state->crtc_h;
  84 +       plane->state->crtc_w = new_state->crtc_w;
  85 +       plane->state->src_x = new_state->src_x;
  86 +       plane->state->src_y = new_state->src_y;
  87 +       plane->state->src_h = new_state->src_h;
  88 +       plane->state->src_w = new_state->src_w;
  89 +       swap(plane->state->fb, new_state->fb);
  90
  91         if (vop->is_enabled) {
  92                 rockchip_drm_psr_inhibit_get_state(new_state->state);
  93 @@ -955,9 +943,22 @@ static void vop_plane_atomic_async_updat
  94                 vop_cfg_done(vop);
  95                 spin_unlock(&vop->reg_lock);
  96                 rockchip_drm_psr_inhibit_put_state(new_state->state);
  97 -       }
  98
  99 -       plane->funcs->atomic_destroy_state(plane, plane_state);
 100 +               /*
 101 +                * A scanout can still be occurring, so we can't drop the
 102 +                * reference to the old framebuffer. To solve this we get a
 103 +                * reference to old_fb and set a worker to release it later.
 104 +                * FIXME: if we perform 500 async_update calls before the
 105 +                * vblank, then we can have 500 different framebuffers waiting
 106 +                * to be released.
 107 +                */
 108 +               if (old_fb && plane->state->fb != old_fb) {
 109 +                       drm_framebuffer_get(old_fb);
 110 +                       WARN_ON(drm_crtc_vblank_get(plane->state->crtc) != 0);
 111 +                       drm_flip_work_queue(&vop->fb_unref_work, old_fb);
 112 +                       set_bit(VOP_PENDING_FB_UNREF, &vop->pending);
 113 +               }
 114 +       }
 115  }
 116
 117  static const struct drm_plane_helper_funcs plane_helper_funcs = {