From: Jeykumar Sankaran <jsanka@xxxxxxxxxxxxxx> commit 968d81a64a883af2d16dd3f8a6ad6b67db2fde58 upstream. drm connector notifies userspace on hotplug event prematurely before late_register and mode_object register completes. This leads to a race between userspace and kernel on updating the IDR list. So, move the notification to end of connector register. Signed-off-by: Jeykumar Sankaran <jsanka@xxxxxxxxxxxxxx> Signed-off-by: Steve Cohen <cohens@xxxxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/1591155451-10393-1-git-send-email-jsanka@xxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/drm_connector.c | 5 +++++ drivers/gpu/drm/drm_sysfs.c | 3 --- 2 files changed, 5 insertions(+), 3 deletions(-) --- a/drivers/gpu/drm/drm_connector.c +++ b/drivers/gpu/drm/drm_connector.c @@ -27,6 +27,7 @@ #include <drm/drm_print.h> #include <drm/drm_drv.h> #include <drm/drm_file.h> +#include <drm/drm_sysfs.h> #include <linux/uaccess.h> @@ -511,6 +512,10 @@ int drm_connector_register(struct drm_co drm_mode_object_register(connector->dev, &connector->base); connector->registration_state = DRM_CONNECTOR_REGISTERED; + + /* Let userspace know we have a new connector */ + drm_sysfs_hotplug_event(connector->dev); + goto unlock; err_debugfs: --- a/drivers/gpu/drm/drm_sysfs.c +++ b/drivers/gpu/drm/drm_sysfs.c @@ -293,9 +293,6 @@ int drm_sysfs_connector_add(struct drm_c return PTR_ERR(connector->kdev); } - /* Let userspace know we have a new connector */ - drm_sysfs_hotplug_event(dev); - if (connector->ddc) return sysfs_create_link(&connector->kdev->kobj, &connector->ddc->dev.kobj, "ddc");
