target/linux/brcm2708/patches-4.4/0099-drm-vc4-Remove-extra-barrier-s-aroudn-CTnCA-CTnEA-se.patch

   1 From 7ab57c24a8c094163c2a5da180edbba0c45b5765 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] drm/vc4: Remove extra barrier()s aroudn CTnCA/CTnEA setup.
   5
   6 The writel() that these expand to already does barriers.
   7
   8 Signed-off-by: Eric Anholt <eric@anholt.net>
   9 ---
  10  drivers/gpu/drm/vc4/vc4_gem.c | 9 +++------
  11  1 file changed, 3 insertions(+), 6 deletions(-)
  12
  13 --- a/drivers/gpu/drm/vc4/vc4_gem.c
  14 +++ b/drivers/gpu/drm/vc4/vc4_gem.c
  15 @@ -104,14 +104,11 @@ submit_cl(struct drm_device *dev, uint32
  16  {
  17         struct vc4_dev *vc4 = to_vc4_dev(dev);
  18
  19 -       V3D_WRITE(V3D_CTNCA(thread), start);
  20 -       barrier();
  21 -
  22 -       /* Set the end address of the control list.  Writing this
  23 -        * register is what starts the job.
  24 +       /* Set the current and end address of the control list.
  25 +        * Writing the end register is what starts the job.
  26          */
  27 +       V3D_WRITE(V3D_CTNCA(thread), start);
  28         V3D_WRITE(V3D_CTNEA(thread), end);
  29 -       barrier();
  30  }
  31
  32  int