The current CRTC state reset hook in vc4 allocates a vc4_crtc_state structure as a drm_crtc_state, and relies on the fact that vc4_crtc_state embeds drm_crtc_state as its first member, and therefore can be safely casted. However, this is pretty fragile especially since there's no check for this in place, and we're going to need to access vc4_crtc_state member at reset so this looks like a good occasion to make it more robust. Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx> Tested-by: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx> --- Changes from v1: - new patch --- drivers/gpu/drm/vc4/vc4_crtc.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c index a393f93390a2..7ef20adedee5 100644 --- a/drivers/gpu/drm/vc4/vc4_crtc.c +++ b/drivers/gpu/drm/vc4/vc4_crtc.c @@ -852,11 +852,18 @@ void vc4_crtc_destroy_state(struct drm_crtc *crtc, void vc4_crtc_reset(struct drm_crtc *crtc) { + struct vc4_crtc_state *vc4_crtc_state; + if (crtc->state) vc4_crtc_destroy_state(crtc, crtc->state); - crtc->state = kzalloc(sizeof(struct vc4_crtc_state), GFP_KERNEL); - if (crtc->state) - __drm_atomic_helper_crtc_reset(crtc, crtc->state); + + vc4_crtc_state = kzalloc(sizeof(*vc4_crtc_state), GFP_KERNEL); + if (!vc4_crtc_state) { + crtc->state = NULL; + return; + } + + __drm_atomic_helper_crtc_reset(crtc, &vc4_crtc_state->base); } static const struct drm_crtc_funcs vc4_crtc_funcs = { -- 2.26.2 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel