On Wed, Sep 30, 2026 at 08:41:45PM +0800, Xilin Wu wrote: > Bridge connectors can attach the max bpc property before their atomic > state is allocated by drm_mode_config_reset(). Unconditionally updating > connector->state in drm_connector_attach_max_bpc_property() dereferences > a NULL pointer in this case. Adding max bpc support to MSM DP and eDP > exposes this during display initialization, before a framebuffer console > is available. > > Only update an existing state when attaching the property. Initialize > max_requested_bpc and max_bpc from the property range when creating a > connector state so that deferred allocation and subsequent resets both > restore the default. Avoid leaving the bit depth at zero after reset, > which would otherwise cause valid display configurations to be rejected. > > With MSM DP max bpc support applied, this also restores boot on the Lenovo > Yoga Slim 7x.
Hmm? > > Assisted-by: LLM > Signed-off-by: Xilin Wu <[email protected]> Can we rather update drm_bridge_connector_init() to register this property in non-HDMI cases if max_bpc is more than 8? > --- > drivers/gpu/drm/drm_atomic_state_helper.c | 5 +++++ > drivers/gpu/drm/drm_connector.c | 6 ++++-- > 2 files changed, 9 insertions(+), 2 deletions(-) > -- With best wishes Dmitry
