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

[ Upstream commit 1342b5b23da9559a1578978eaff7f797d8a87d91 ]

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: 624b4b48d9d8 ("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
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Samuel Holland 2022-06-15 00:42:53 -05:00 committed by Greg Kroah-Hartman
parent b03607437e
commit 0eef1dcb97

View File

@ -72,7 +72,6 @@ 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);
@ -113,6 +112,8 @@ static int sun4i_drv_bind(struct device *dev)
drm_fbdev_generic_setup(drm, 32);
dev_set_drvdata(dev, drm);
return 0;
finish_poll:
@ -129,6 +130,7 @@ 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);