Re: [v1,1/2] drm/mediatek: Fixup external display black screen issue

[Yongqiang Niu]

On Thu, 2019-12-05 at 14:15 +0800, Hsin-Yi Wang wrote:
> On Wed, Nov 27, 2019 at 1:17 AM <yongqiang.niu@xxxxxxxxxxxx> wrote:
> >
> > From: Yongqiang Niu <yongqiang.niu@xxxxxxxxxxxx>
> >
> > Problem:
> > overlay hangup when external display hotplut test
> >
> > Fix:
> > disable overlay when crtc disable
> >
> > Signed-off-by: Yongqiang Niu <yongqiang.niu@xxxxxxxxxxxx>
> > ---
> >  drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 39 +++++++++++++++++++++------------
> >  1 file changed, 25 insertions(+), 14 deletions(-)
> >
> > --
> > 1.8.1.1.dirty
> >
> > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> > index 4fb346c..7eca02f 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> > @@ -369,6 +369,20 @@ static int mtk_crtc_ddp_hw_init(struct mtk_drm_crtc *mtk_crtc)
> >         mtk_disp_mutex_add_comp(mtk_crtc->mutex, mtk_crtc->ddp_comp[i]->id);
> >         mtk_disp_mutex_enable(mtk_crtc->mutex);
> >
> > +       /* Initially configure all planes */
> > +       for (i = 0; i < mtk_crtc->layer_nr; i++) {
> > +               struct drm_plane *plane = &mtk_crtc->planes[i];
> > +               struct mtk_plane_state *plane_state;
> > +               struct mtk_ddp_comp *comp;
> > +               unsigned int local_layer;
> > +
> > +               plane_state = to_mtk_plane_state(plane->state);
> > +               comp = mtk_drm_ddp_comp_for_plane(crtc, plane, &local_layer);
> > +               if (comp)
> > +                       mtk_ddp_comp_layer_config(comp, local_layer,
> > +                                                 plane_state, NULL);
> > +       }
> > +
> >         for (i = 0; i < mtk_crtc->ddp_comp_nr; i++) {
> >                 struct mtk_ddp_comp *comp = mtk_crtc->ddp_comp[i];
> >                 enum mtk_ddp_comp_id prev;
> > @@ -385,20 +399,6 @@ static int mtk_crtc_ddp_hw_init(struct mtk_drm_crtc *mtk_crtc)
> >                 mtk_ddp_comp_start(comp);
> >         }
> >
> > -       /* Initially configure all planes */
> > -       for (i = 0; i < mtk_crtc->layer_nr; i++) {
> > -               struct drm_plane *plane = &mtk_crtc->planes[i];
> > -               struct mtk_plane_state *plane_state;
> > -               struct mtk_ddp_comp *comp;
> > -               unsigned int local_layer;
> > -
> > -               plane_state = to_mtk_plane_state(plane->state);
> > -               comp = mtk_drm_ddp_comp_for_plane(crtc, plane, &local_layer);
> > -               if (comp)
> > -                       mtk_ddp_comp_layer_config(comp, local_layer,
> > -                                                 plane_state, NULL);
> > -       }
> > -
> >         return 0;
> >
> >  err_mutex_unprepare:
> > @@ -607,10 +607,21 @@ static void mtk_drm_crtc_atomic_disable(struct drm_crtc *crtc,
> >         for (i = 0; i < mtk_crtc->layer_nr; i++) {
> >                 struct drm_plane *plane = &mtk_crtc->planes[i];
> >                 struct mtk_plane_state *plane_state;
> > +               struct mtk_ddp_comp *comp = mtk_crtc->ddp_comp[0];
> > +               unsigned int comp_layer_nr = mtk_ddp_comp_layer_nr(comp);
> > +               unsigned int local_layer;
> >
> >                 plane_state = to_mtk_plane_state(plane->state);
> >                 plane_state->pending.enable = false;
> >                 plane_state->pending.config = true;
> > +
> > +               if (i >= comp_layer_nr) {
> > +                       comp = mtk_crtc->ddp_comp[1];
> > +                       local_layer = i - comp_layer_nr;
> > +               } else
> > +                       local_layer = i;
> > +               mtk_ddp_comp_layer_config(comp, local_layer,
> > +                                         plane_state, NULL);
> This part should be moved to mtk_crtc_ddp_hw_fini(), or at least
> called after drm_crtc_vblank_off(). Otherwise we would see
> drm_wait_one_vblank warnings on 8173 when display turns off.
> 
> [   25.696182] Call trace:
> [   25.698624]  drm_wait_one_vblank+0x1f0/0x1fc
> [   25.702886]  drm_crtc_wait_one_vblank+0x20/0x2c
> [   25.707415]  mtk_drm_crtc_atomic_disable+0xf0/0x308
> [   25.712287]  drm_atomic_helper_commit_modeset_disables+0x1b8/0x3c0
> [   25.718461]  mtk_atomic_complete+0x88/0x16c
> [   25.722638]  mtk_atomic_commit+0xa8/0xb0
> [   25.726553]  drm_atomic_commit+0x50/0x5c
> [   25.730469]  drm_atomic_helper_set_config+0x98/0xa0
> [   25.735341]  drm_mode_setcrtc+0x280/0x608
> [   25.739344]  drm_ioctl_kernel+0xcc/0x10c
> [   25.743261]  drm_ioctl+0x240/0x3c0
> [   25.746658]  drm_compat_ioctl+0xd8/0xe8
> [   25.750487]  __se_compat_sys_ioctl+0x100/0x26fc
> [   25.755009]  __arm64_compat_sys_ioctl+0x20/0x2c
> [   25.759534]  el0_svc_common+0xa4/0x154
> [   25.763277]  el0_svc_compat_handler+0x2c/0x38
> [   25.767628]  el0_svc_compat+0x8/0x18
> [   25.771195] ---[ end trace f4619fdac8f1c0ff ]---
> 
> >
please double confirm is this dump stack log is ruining on MT8173 real
IC or not.
if yes, that may caused ovl hang when disable layer not in blanking,
then cause vblank time out.
i will disable overlay with cmdq in next version.


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