target/linux/brcm2708/patches-4.4/0100-drm-vc4-Remove-extra-barrier-s-aroudn-CTnCA-CTnEA-se.patch

   1 From d102d0e145b58bccbea52e89bbe52dcefc044aaa Mon Sep 17 00:00:00 2001
   2 From: Eric Anholt <eric@anholt.net>
   3 Date: Fri, 23 Oct 2015 12:33:43 +0100
   4 Subject: [PATCH 100/170] drm/vc4: Remove extra barrier()s aroudn CTnCA/CTnEA
   5  setup.
   6
   7 The writel() that these expand to already does barriers.
   8
   9 Signed-off-by: Eric Anholt <eric@anholt.net>
  10 ---
  11  drivers/gpu/drm/vc4/vc4_gem.c | 9 +++------
  12  1 file changed, 3 insertions(+), 6 deletions(-)
  13
  14 --- a/drivers/gpu/drm/vc4/vc4_gem.c
  15 +++ b/drivers/gpu/drm/vc4/vc4_gem.c
  16 @@ -104,14 +104,11 @@ submit_cl(struct drm_device *dev, uint32
  17  {
  18         struct vc4_dev *vc4 = to_vc4_dev(dev);
  19
  20 -       V3D_WRITE(V3D_CTNCA(thread), start);
  21 -       barrier();
  22 -
  23 -       /* Set the end address of the control list.  Writing this
  24 -        * register is what starts the job.
  25 +       /* Set the current and end address of the control list.
  26 +        * Writing the end register is what starts the job.
  27          */
  28 +       V3D_WRITE(V3D_CTNCA(thread), start);
  29         V3D_WRITE(V3D_CTNEA(thread), end);
  30 -       barrier();
  31  }
  32
  33  int