releases/4.4.36/drm-radeon-ensure-vblank-interrupt-is-enabled-on-dpms-transition-to-on.patch

   1 From michel@daenzer.net  Tue Nov 29 16:29:26 2016
   2 From: Michel Dänzer <michel@daenzer.net>
   3 Date: Tue, 29 Nov 2016 18:40:20 +0900
   4 Subject: [PATCH] drm/radeon: Ensure vblank interrupt is enabled on DPMS transition to on
   5 To: stable@vger.kernel.org
   6 Cc: Max Staudt <mstaudt@suse.de>
   7 Message-ID: <20161129094020.27353-1-michel@daenzer.net>
   8
   9 From: Michel Dänzer <michel@daenzer.net>
  10
  11 NOTE: This patch only applies to 4.5.y or older kernels. With newer
  12 kernels, this problem cannot happen because the driver now uses
  13 drm_crtc_vblank_on/off instead of drm_vblank_pre/post_modeset[0]. I
  14 consider this patch safer for older kernels than backporting the API
  15 change, because drm_crtc_vblank_on/off had various issues in older
  16 kernels, and I'm not sure all fixes for those have been backported to
  17 all stable branches where this patch could be applied.
  18
  19     ---------------------
  20
  21 Fixes the vblank interrupt being disabled when it should be on, which
  22 can cause at least the following symptoms:
  23
  24 * Hangs when running 'xset dpms force off' in a GNOME session with
  25   gnome-shell using DRI2.
  26 * RandR 1.4 slave outputs freezing with garbage displayed using
  27   xf86-video-ati 7.8.0 or newer.
  28
  29 [0] See upstream commit:
  30
  31 commit 777e3cbc791f131806d9bf24b3325637c7fc228d
  32 Author: Daniel Vetter <daniel.vetter@ffwll.ch>
  33 Date:   Thu Jan 21 11:08:57 2016 +0100
  34
  35     drm/radeon: Switch to drm_vblank_on/off
  36
  37 Reported-and-Tested-by: Max Staudt <mstaudt@suse.de>
  38 Reviewed-by: Daniel Vetter <daniel@ffwll.ch>
  39 Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
  40 Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
  41 ---
  42  drivers/gpu/drm/radeon/atombios_crtc.c      |    2 ++
  43  drivers/gpu/drm/radeon/radeon_legacy_crtc.c |    2 ++
  44  2 files changed, 4 insertions(+)
  45
  46 --- a/drivers/gpu/drm/radeon/atombios_crtc.c
  47 +++ b/drivers/gpu/drm/radeon/atombios_crtc.c
  48 @@ -275,6 +275,8 @@ void atombios_crtc_dpms(struct drm_crtc
  49                         atombios_enable_crtc_memreq(crtc, ATOM_ENABLE);
  50                 atombios_blank_crtc(crtc, ATOM_DISABLE);
  51                 drm_vblank_post_modeset(dev, radeon_crtc->crtc_id);
  52 +               /* Make sure vblank interrupt is still enabled if needed */
  53 +               radeon_irq_set(rdev);
  54                 radeon_crtc_load_lut(crtc);
  55                 break;
  56         case DRM_MODE_DPMS_STANDBY:
  57 --- a/drivers/gpu/drm/radeon/radeon_legacy_crtc.c
  58 +++ b/drivers/gpu/drm/radeon/radeon_legacy_crtc.c
  59 @@ -331,6 +331,8 @@ static void radeon_crtc_dpms(struct drm_
  60                         WREG32_P(RADEON_CRTC_EXT_CNTL, crtc_ext_cntl, ~(mask | crtc_ext_cntl));
  61                 }
  62                 drm_vblank_post_modeset(dev, radeon_crtc->crtc_id);
  63 +               /* Make sure vblank interrupt is still enabled if needed */
  64 +               radeon_irq_set(rdev);
  65                 radeon_crtc_load_lut(crtc);
  66                 break;
  67         case DRM_MODE_DPMS_STANDBY: