[PATCH 4.10 62/81] drm/vc4: Allocate the right amount of space for boot-time CRTC state.

Greg Kroah-Hartman
2017-04-06T08:46:44Z

From: Eric Anholt <eric@anholt.net>

commit 6d6e500391875cc372336c88e9a8af377be19c36 upstream.

Without this, the first modeset would dereference past the allocation
when trying to free the mm node.

Signed-off-by: Eric Anholt <eric@anholt.net>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170328201343.4884-1-eric@anholt.net
Fixes: d8dbf44f13b9 ("drm/vc4: Make the CRTCs cooperate on allocating display lists.")
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/gpu/drm/vc4/vc4_crtc.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -842,6 +842,17 @@ static void vc4_crtc_destroy_state(struc
drm_atomic_helper_crtc_destroy_state(crtc, state);
}

+static void
+vc4_crtc_reset(struct drm_crtc *crtc)
+{
+ if (crtc->state)
+ __drm_atomic_helper_crtc_destroy_state(crtc->state);
+
+ crtc->state = kzalloc(sizeof(struct vc4_crtc_state), GFP_KERNEL);
+ if (crtc->state)
+ crtc->state->crtc = crtc;
+}
+
static const struct drm_crtc_funcs vc4_crtc_funcs = {
.set_config = drm_atomic_helper_set_config,
.destroy = vc4_crtc_destroy,
@@ -849,7 +860,7 @@ static const struct drm_crtc_funcs vc4_c
.set_property = NULL,
.cursor_set = NULL, /* handled by drm_mode_cursor_universal */
.cursor_move = NULL, /* handled by drm_mode_cursor_universal */
- .reset = drm_atomic_helper_crtc_reset,
+ .reset = vc4_crtc_reset,
.atomic_duplicate_state = vc4_crtc_duplicate_state,
.atomic_destroy_state = vc4_crtc_destroy_state,
.gamma_set = vc4_crtc_gamma_set,