target/linux/bcm27xx/patches-5.4/950-0268-drm-vc4-Ignore-HVS-unless-initialised.patch

   1 From cad68ea70d649cff90102022c5d161bf84e4ed16 Mon Sep 17 00:00:00 2001
   2 From: Phil Elwell <phil@raspberrypi.org>
   3 Date: Fri, 19 Jul 2019 14:29:28 +0100
   4 Subject: [PATCH] drm/vc4: Ignore HVS unless initialised
   5
   6 An upstream commit to report HVS underruns causes VC4 in firmware KMS
   7 mode to cross into the HVS side, where it crashes due to a NULL hvs
   8 pointer.
   9
  10 Make the underrun masking conditional on the hvs pointer being
  11 initialised.
  12
  13 Fixes: 531a1b622da9 ("drm/vc4: Report HVS underrun errors")
  14
  15 Signed-off-by: Phil Elwell <phil@raspberrypi.org>
  16 ---
  17  drivers/gpu/drm/vc4/vc4_crtc.c | 3 ++-
  18  drivers/gpu/drm/vc4/vc4_kms.c  | 2 +-
  19  2 files changed, 3 insertions(+), 2 deletions(-)
  20
  21 --- a/drivers/gpu/drm/vc4/vc4_crtc.c
  22 +++ b/drivers/gpu/drm/vc4/vc4_crtc.c
  23 @@ -801,7 +801,8 @@ static void vc4_crtc_handle_page_flip(st
  24                  * the CRTC and encoder already reconfigured, leading to
  25                  * underruns. This can be seen when reconfiguring the CRTC.
  26                  */
  27 -               vc4_hvs_unmask_underrun(dev, vc4_crtc->channel);
  28 +               if (vc4->hvs)
  29 +                       vc4_hvs_unmask_underrun(dev, vc4_crtc->channel);
  30         }
  31         spin_unlock_irqrestore(&dev->event_lock, flags);
  32  }
  33 --- a/drivers/gpu/drm/vc4/vc4_kms.c
  34 +++ b/drivers/gpu/drm/vc4/vc4_kms.c
  35 @@ -156,7 +156,7 @@ vc4_atomic_complete_commit(struct drm_at
  36         struct vc4_crtc *vc4_crtc;
  37         int i;
  38
  39 -       for (i = 0; i < dev->mode_config.num_crtc; i++) {
  40 +       for (i = 0; vc4->hvs && i < dev->mode_config.num_crtc; i++) {
  41                 if (!state->crtcs[i].ptr || !state->crtcs[i].commit)
  42                         continue;
  43