Hi Paul,

Thank you for the patch.

On Sun, Jan 24, 2021 at 08:55:51AM +0000, Paul Cercueil wrote:

Since the encoders have been devm-allocated, they will be freed way before drm_mode_config_cleanup() is called. To avoid use-after-free conditions, we then must ensure that drm_encoder_cleanup() is called before the encoders are freed.

v2: Use the new __drmm_simple_encoder_alloc() function

v3: Use the new drmm_plain_simple_encoder_alloc() macro

Fixes: c369cb27c267 ("drm/ingenic: Support multiple panels/bridges") Cc: stable@vger.kernel.org # 5.8+ Signed-off-by: Paul Cercueil paul@crapouillou.net

Reviewed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com

---

Notes: Use the V1 of this patch to fix v5.11 and older kernels. This V3 only applies on the current drm-misc-next branch.

drivers/gpu/drm/ingenic/ingenic-drm-drv.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c index 7bb31fbee29d..b23011c1c5d9 100644 --- a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c +++ b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c @@ -1014,20 +1014,17 @@ static int ingenic_drm_bind(struct device *dev, bool has_components) bridge = devm_drm_panel_bridge_add_typed(dev, panel, DRM_MODE_CONNECTOR_DPI);

• encoder = devm_kzalloc(dev, sizeof(*encoder), GFP_KERNEL);
  

• if (!encoder)
  

• 	return -ENOMEM;
  

• encoder = drmm_plain_simple_encoder_alloc(drm, DRM_MODE_ENCODER_DPI);
  

• if (IS_ERR(encoder)) {
  

• 	ret = PTR_ERR(encoder);
  

• 	dev_err(dev, "Failed to init encoder: %d\n", ret);
  

• 	return ret;
  

• }
  

encoder->possible_crtcs = 1; drm_encoder_helper_add(encoder, &ingenic_drm_encoder_helper_funcs);

• ret = drm_simple_encoder_init(drm, encoder, DRM_MODE_ENCODER_DPI);
  

• if (ret) {
  

• 	dev_err(dev, "Failed to init encoder: %d\n", ret);
  

• 	return ret;
  

• }
  

• ret = drm_bridge_attach(encoder, bridge, NULL, 0); if (ret) { dev_err(dev, "Unable to attach bridge\n");