From 5f5dd28b3159de16b1995e4c0e93a6af7d3d18ea Mon Sep 17 00:00:00 2001 From: Lyude Date: Tue, 31 May 2016 12:49:07 -0400 Subject: [PATCH] drm/atomic: Verify connector->funcs != NULL when clearing states Unfortunately since we don't have Dave's connector refcounting patch here yet, it's very possible that drm_atomic_state_default_clear() could get called by intel_display_resume() when intel_dp_mst_destroy_connector() isn't completely finished destroying an mst connector, but has already finished setting connector->funcs to NULL. As such, we need to treat the connector like it's already been destroyed and just skip it, otherwise we'll end up dereferencing a NULL pointer. This fix is only required for 4.6 and below. David Airlie's patchseries for 4.7 to add connector reference counting provides a more proper fix for this. Changes since v1: - Fix leftover whitespace Upstream fix: 0552f7651bc2 ("drm/i915/mst: use reference counted connectors. (v3)") Reviewed-by: Daniel Vetter Signed-off-by: Lyude --- drivers/gpu/drm/drm_atomic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c index 9a7b44616b552..ee9914d0e5c66 100644 --- a/drivers/gpu/drm/drm_atomic.c +++ b/drivers/gpu/drm/drm_atomic.c @@ -138,7 +138,7 @@ void drm_atomic_state_default_clear(struct drm_atomic_state *state) for (i = 0; i < state->num_connector; i++) { struct drm_connector *connector = state->connectors[i]; - if (!connector) + if (!connector || !connector->funcs) continue; /* -- 2.47.2