diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c index bf4667481935..c61dff594195 100644 --- a/drivers/gpu/drm/vc4/vc4_crtc.c +++ b/drivers/gpu/drm/vc4/vc4_crtc.c @@ -760,6 +760,7 @@ static irqreturn_t vc4_crtc_irq_handler(int irq, void *data) struct vc4_async_flip_state { struct drm_crtc *crtc; struct drm_framebuffer *fb; + struct drm_framebuffer *old_fb; struct drm_pending_vblank_event *event; struct vc4_seqno_cb cb; @@ -789,6 +790,23 @@ vc4_async_page_flip_complete(struct vc4_seqno_cb *cb) drm_crtc_vblank_put(crtc); drm_framebuffer_put(flip_state->fb); + + /* Decrement the BO usecnt in order to keep the inc/dec calls balanced + * when the planes are updated through the async update path. + * FIXME: we should move to generic async-page-flip when it's + * available, so that we can get rid of this hand-made cleanup_fb() + * logic. + */ + if (flip_state->old_fb) { + struct drm_gem_cma_object *cma_bo; + struct vc4_bo *bo; + + cma_bo = drm_fb_cma_get_gem_obj(flip_state->old_fb, 0); + bo = to_vc4_bo(&cma_bo->base); + vc4_bo_dec_usecnt(bo); + drm_framebuffer_put(flip_state->old_fb); + } + kfree(flip_state); up(&vc4->async_modeset); @@ -813,9 +831,22 @@ static int vc4_async_page_flip(struct drm_crtc *crtc, struct drm_gem_cma_object *cma_bo = drm_fb_cma_get_gem_obj(fb, 0); struct vc4_bo *bo = to_vc4_bo(&cma_bo->base); + /* Increment the BO usecnt here, so that we never end up with an + * unbalanced number of vc4_bo_{dec,inc}_usecnt() calls when the + * plane is later updated through the non-async path. + * FIXME: we should move to generic async-page-flip when it's + * available, so that we can get rid of this hand-made prepare_fb() + * logic. + */ + ret = vc4_bo_inc_usecnt(bo); + if (ret) + return ret; + flip_state = kzalloc(sizeof(*flip_state), GFP_KERNEL); - if (!flip_state) + if (!flip_state) { + vc4_bo_dec_usecnt(bo); return -ENOMEM; + } drm_framebuffer_get(fb); flip_state->fb = fb; @@ -826,10 +857,23 @@ static int vc4_async_page_flip(struct drm_crtc *crtc, ret = down_interruptible(&vc4->async_modeset); if (ret) { drm_framebuffer_put(fb); + vc4_bo_dec_usecnt(bo); kfree(flip_state); return ret; } + /* Save the current FB before it's replaced by the new one in + * drm_atomic_set_fb_for_plane(). We'll need the old FB in + * vc4_async_page_flip_complete() to decrement the BO usecnt and keep + * it consistent. + * FIXME: we should move to generic async-page-flip when it's + * available, so that we can get rid of this hand-made cleanup_fb() + * logic. + */ + flip_state->old_fb = plane->state->fb; + if (flip_state->old_fb) + drm_framebuffer_get(flip_state->old_fb); + WARN_ON(drm_crtc_vblank_get(crtc) != 0); /* Immediately update the plane's legacy fb pointer, so that later