The patch below does not apply to the 5.12-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From e488b1023a4a4eab15b905871cf8e81f00336ed7 Mon Sep 17 00:00:00 2001
From: Paul Cercueil paul@crapouillou.net Date: Sat, 27 Mar 2021 11:57:42 +0000 Subject: [PATCH] drm/ingenic: Register devm action to cleanup encoders
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
v4: Use drmm_plain_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 Link: https://patchwork.freedesktop.org/patch/msgid/20210327115742.18986-4-paul@cr...
diff --git a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c index d60e1eefc9d1..29742ec5ab95 100644 --- a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c +++ b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c @@ -24,6 +24,7 @@ #include <drm/drm_crtc.h> #include <drm/drm_crtc_helper.h> #include <drm/drm_drv.h> +#include <drm/drm_encoder.h> #include <drm/drm_gem_cma_helper.h> #include <drm/drm_fb_cma_helper.h> #include <drm/drm_fb_helper.h> @@ -37,7 +38,6 @@ #include <drm/drm_plane.h> #include <drm/drm_plane_helper.h> #include <drm/drm_probe_helper.h> -#include <drm/drm_simple_kms_helper.h> #include <drm/drm_vblank.h>
struct ingenic_dma_hwdesc { @@ -1024,20 +1024,17 @@ 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_encoder_alloc(drm, NULL, DRM_MODE_ENCODER_DPI, NULL); + 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");