target/linux/bcm27xx/patches-5.15/950-0621-drm-vc4-hvs-Ignore-atomic_flush-if-we-re-disabled.patch

   1 From ba067c30a6456a28c42f74d2134ce9a54a10337f Mon Sep 17 00:00:00 2001
   2 From: Maxime Ripard <maxime@cerno.tech>
   3 Date: Mon, 6 Dec 2021 16:32:10 +0100
   4 Subject: [PATCH] drm/vc4: hvs: Ignore atomic_flush if we're disabled
   5
   6 atomic_flush will be called for each CRTC even if they aren't enabled.
   7
   8 The whole code we have there will thus run without a properly affected
   9 channel, which can then result in all sorts of weird behaviour.
  10
  11 Signed-off-by: Maxime Ripard <maxime@cerno.tech>
  12 ---
  13  drivers/gpu/drm/vc4/vc4_hvs.c | 3 +++
  14  1 file changed, 3 insertions(+)
  15
  16 --- a/drivers/gpu/drm/vc4/vc4_hvs.c
  17 +++ b/drivers/gpu/drm/vc4/vc4_hvs.c
  18 @@ -686,6 +686,9 @@ void vc4_hvs_atomic_flush(struct drm_crt
  19         u32 __iomem *dlist_start = vc4->hvs->dlist + vc4_state->mm.start;
  20         u32 __iomem *dlist_next = dlist_start;
  21
  22 +       if (vc4_state->assigned_channel == VC4_HVS_CHANNEL_DISABLED)
  23 +               return;
  24 +
  25         if (debug_dump_regs) {
  26                 DRM_INFO("CRTC %d HVS before:\n", drm_crtc_index(crtc));
  27                 vc4_hvs_dump_state(dev);