drm/connector: notify userspace on hotplug after register complete (968d81a6) · Commits · 戴 / test

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@codeaurora.org> Signed-off-by:

Steve Cohen <cohens@codeaurora.org> Cc: stable@vger.kernel.org Signed-off-by:

Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/1591155451-10393-1-git-send-email-jsanka@codeaurora.org

drivers/gpu/drm/drm_connector.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -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>

		@@ -523,6 +524,10 @@ int drm_connector_register(struct drm_connector *connector)
		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:

drivers/gpu/drm/drm_sysfs.c

+0 −3

Original line number	Diff line number	Diff line
		@@ -291,9 +291,6 @@ int drm_sysfs_connector_add(struct drm_connector *connector)
		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");

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