When disabling overlay plane in mxsfb_plane_overlay_atomic_update(),
overlay plane's framebuffer pointer is NULL. So, dereferencing it would
cause a kernel Oops(NULL pointer dereferencing). Fix the issue by
disabling overlay plane in mxsfb_plane_overlay_atomic_disable() instead.
Fixes: cb285a5348e7 ("drm: mxsfb: Replace mxsfb_get_fb_paddr() with drm_fb_cma_get_gem_addr()")
Signed-off-by: Liu Ying <victor.liu@xxxxxxx>
---
drivers/gpu/drm/mxsfb/mxsfb_kms.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/gpu/drm/mxsfb/mxsfb_kms.c b/drivers/gpu/drm/mxsfb/mxsfb_kms.c
index 3bcc9c0f2019..7ed2516b6de0 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_kms.c
+++ b/drivers/gpu/drm/mxsfb/mxsfb_kms.c
@@ -611,6 +611,14 @@ static void mxsfb_plane_overlay_atomic_update(struct drm_plane *plane,
writel(ctrl, mxsfb->base + LCDC_AS_CTRL);
}
+static void mxsfb_plane_overlay_atomic_disable(struct drm_plane *plane,
+ struct drm_atomic_state *state)
+{
+ struct mxsfb_drm_private *mxsfb = to_mxsfb_drm_private(plane->dev);
+
+ writel(0, mxsfb->base + LCDC_AS_CTRL);
+}
+
static bool mxsfb_format_mod_supported(struct drm_plane *plane,
uint32_t format,
uint64_t modifier)
@@ -626,6 +634,7 @@ static const struct drm_plane_helper_funcs mxsfb_plane_primary_helper_funcs = {
static const struct drm_plane_helper_funcs mxsfb_plane_overlay_helper_funcs = {
.atomic_check = mxsfb_plane_atomic_check,
.atomic_update = mxsfb_plane_overlay_atomic_update,
+ .atomic_disable = mxsfb_plane_overlay_atomic_disable,
};
static const struct drm_plane_funcs mxsfb_plane_funcs = {
--
2.37.1
