From: Abhishek Pandit-Subedi <abhishekpandit@xxxxxxxxxxxx> [ Upstream commit 99516f76db48e1a9d54cdfed63c1babcee4e71a5 ] ucsi_register_altmode checks IS_ERR for the alt pointer and treats NULL as valid. When CONFIG_TYPEC_DP_ALTMODE is not enabled, ucsi_register_displayport returns NULL which causes a NULL pointer dereference in trace. Rather than return NULL, call typec_port_register_altmode to register DisplayPort alternate mode as a non-controllable mode when CONFIG_TYPEC_DP_ALTMODE is not enabled. Reviewed-by: Benson Leung <bleung@xxxxxxxxxxxx> Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@xxxxxxxxxxxx> Signed-off-by: Jameson Thies <jthies@xxxxxxxxxx> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> Link: https://lore.kernel.org/r/20240510201244.2968152-2-jthies@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/usb/typec/ucsi/ucsi.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h index de87d0b8319d0..179ad343f42f0 100644 --- a/drivers/usb/typec/ucsi/ucsi.h +++ b/drivers/usb/typec/ucsi/ucsi.h @@ -446,7 +446,7 @@ ucsi_register_displayport(struct ucsi_connector *con, bool override, int offset, struct typec_altmode_desc *desc) { - return NULL; + return typec_port_register_altmode(con->port, desc); } static inline void -- 2.43.0
