drm: Avoid connector reference imbalance on error path (e2d800a3) · Commits · 戴 / test

Whilst looking at the fallout from using connector references for atomic, I noticed that there is an early return buried in drm_atomic_set_crtc_for_connector() that if hit could cause us to leak a reference on the connector. Fixes: (drm/atomic: use connector references (v3)) Signed-off-by:

Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Stone <daniels@collabora.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Dave Airlie <airlied@redhat.com> Signed-off-by:

Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1462535265-13058-1-git-send-email-chris@chris-wilson.co.uk

drivers/gpu/drm/drm_atomic.c

+11 −9

Original line number	Diff line number	Diff line
		@@ -1160,14 +1160,18 @@ drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,
		{
		struct drm_crtc_state *crtc_state;

		if (crtc)
		drm_connector_reference(conn_state->connector);
		if (conn_state->crtc && conn_state->crtc != crtc) {
		if (conn_state->crtc == crtc)
		return 0;

		if (conn_state->crtc) {
		crtc_state = drm_atomic_get_existing_crtc_state(conn_state->state,
		conn_state->crtc);

		crtc_state->connector_mask &=
		~(1 << drm_connector_index(conn_state->connector));

		drm_connector_unreference(conn_state->connector);
		conn_state->crtc = NULL;
		}

		if (crtc) {
		@@ -1177,18 +1181,16 @@ drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state,

		crtc_state->connector_mask \|=
		1 << drm_connector_index(conn_state->connector);
		}

		if (conn_state->crtc)
		drm_connector_unreference(conn_state->connector);
		drm_connector_reference(conn_state->connector);
		conn_state->crtc = crtc;

		if (crtc)
		DRM_DEBUG_ATOMIC("Link connector state %p to [CRTC:%d:%s]\n",
		conn_state, crtc->base.id, crtc->name);
		else
		} else {
		DRM_DEBUG_ATOMIC("Link connector state %p to [NOCRTC]\n",
		conn_state);
		}

		return 0;
		}

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