target/linux/brcm2708/patches-4.4/0340-drm-vc4-Fix-get_vblank_counter-with-proper-no-op-for.patch

   1 From 41a242de6e06a106399d2c713dc4114da3532d22 Mon Sep 17 00:00:00 2001
   2 From: Mario Kleiner <mario.kleiner.de@gmail.com>
   3 Date: Fri, 6 May 2016 19:26:05 +0200
   4 Subject: [PATCH 340/423] drm/vc4: Fix get_vblank_counter with proper no-op for
   5  Linux 4.4+
   6
   7 get_vblank_counter hooked up to drm_vblank_count() which alway was
   8 non-sensical but didn't hurt in the past. Since Linux 4.4 it
   9 triggers a WARN_ON_ONCE in drm_update_vblank_count on first vblank
  10 irq disable, so fix it by hooking to drm_vblank_no_hw_counter().
  11
  12 Tested against Raspian kernel 4.4.8 tree on RPi 2B.
  13
  14 Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
  15 Cc: Eric Anholt <eric@anholt.net>
  16 Signed-off-by: Eric Anholt <eric@anholt.net>
  17 ---
  18  drivers/gpu/drm/vc4/vc4_drv.c | 2 +-
  19  1 file changed, 1 insertion(+), 1 deletion(-)
  20
  21 --- a/drivers/gpu/drm/vc4/vc4_drv.c
  22 +++ b/drivers/gpu/drm/vc4/vc4_drv.c
  23 @@ -102,7 +102,7 @@ static struct drm_driver vc4_drm_driver
  24
  25         .enable_vblank = vc4_enable_vblank,
  26         .disable_vblank = vc4_disable_vblank,
  27 -       .get_vblank_counter = drm_vblank_count,
  28 +       .get_vblank_counter = drm_vblank_no_hw_counter,
  29
  30  #if defined(CONFIG_DEBUG_FS)
  31         .debugfs_init = vc4_debugfs_init,