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()") Cc: stable@vger.kernel.org # 5.19+ Signed-off-by: Liu Ying victor.liu@nxp.com --- v1->v2: * Cc stable. (Marek)

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 = {