drm/sun4i: Fix crash during suspend after component bind failure

If the component driver fails to bind, or is unbound, the driver data
for the top-level platform device points to a freed drm_device. If the
system is then suspended, the driver passes this dangling pointer to
drm_mode_config_helper_suspend(), which crashes.

Fix this by only setting the driver data while the platform driver holds
a reference to the drm_device.

Fixes: 624b4b48d9 ("drm: sun4i: Add support for suspending the display driver")
Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220615054254.16352-1-samuel@sholland.org
This commit is contained in:
Samuel Holland 2022-06-15 00:42:53 -05:00 committed by Maxime Ripard
parent 920169041b
commit 1342b5b23d
No known key found for this signature in database
GPG key ID: E3EF0D6F671851C5

View file

@ -73,7 +73,6 @@ static int sun4i_drv_bind(struct device *dev)
goto free_drm;
}
dev_set_drvdata(dev, drm);
drm->dev_private = drv;
INIT_LIST_HEAD(&drv->frontend_list);
INIT_LIST_HEAD(&drv->engine_list);
@ -114,6 +113,8 @@ static int sun4i_drv_bind(struct device *dev)
drm_fbdev_generic_setup(drm, 32);
dev_set_drvdata(dev, drm);
return 0;
finish_poll:
@ -130,6 +131,7 @@ static void sun4i_drv_unbind(struct device *dev)
{
struct drm_device *drm = dev_get_drvdata(dev);
dev_set_drvdata(dev, NULL);
drm_dev_unregister(drm);
drm_kms_helper_poll_fini(drm);
drm_atomic_helper_shutdown(drm);