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Commit 7aedfdd8 authored by Jack Pham's avatar Jack Pham
Browse files

usb: pd: Register power_supply notifier after completing init 



There is a rare but possible chance that just after registering
the psy_changed notifier callback with the power_supply
framework that it could be called immediately, schedule the
usbpd_sm, and execute the worker on another thread, all before
usbpd_create() has completed. Since some structures, notably
pd->rx_lock, haven't been fully initialized yet, this leads
to spin_lock() call accessing uninitialized data. Fix this by
moving the power_supply_reg_notifier() call to the very end
of usbpd_create() after everything has been initialized.

Change-Id: I7d2bc9eca8e7e30dbc656be620a0f4fd8eea2239
Signed-off-by: default avatarJack Pham <jackp@codeaurora.org>
parent 3162449f

drivers/usb/pd/policy_engine.c

+12 −12
Original line number Diff line number Diff line
@@ -2974,11 +2974,6 @@ struct usbpd *usbpd_create(struct device *parent) 
		goto destroy_wq;

	}



	pd->psy_nb.notifier_call = psy_changed;

	ret = power_supply_reg_notifier(&pd->psy_nb);

	if (ret)

		goto put_psy;



	/*

	 * associate extcon with the parent dev as it could have a DT

	 * node which will be useful for extcon_get_edev_by_phandle()
@@ -2987,26 +2982,26 @@ struct usbpd *usbpd_create(struct device *parent) 
	if (IS_ERR(pd->extcon)) {

		usbpd_err(&pd->dev, "failed to allocate extcon device\n");

		ret = PTR_ERR(pd->extcon);

		goto unreg_psy;

		goto put_psy;

	}



	pd->extcon->mutually_exclusive = usbpd_extcon_exclusive;

	ret = devm_extcon_dev_register(parent, pd->extcon);

	if (ret) {

		usbpd_err(&pd->dev, "failed to register extcon device\n");

		goto unreg_psy;

		goto put_psy;

	}



	pd->vbus = devm_regulator_get(parent, "vbus");

	if (IS_ERR(pd->vbus)) {

		ret = PTR_ERR(pd->vbus);

		goto unreg_psy;

		goto put_psy;

	}



	pd->vconn = devm_regulator_get(parent, "vconn");

	if (IS_ERR(pd->vconn)) {

		ret = PTR_ERR(pd->vconn);

		goto unreg_psy;

		goto put_psy;

	}



	pd->vconn_is_external = device_property_present(parent,
@@ -3031,7 +3026,7 @@ struct usbpd *usbpd_create(struct device *parent) 
			&pd->dr_desc);

	if (IS_ERR(pd->dual_role)) {

		usbpd_err(&pd->dev, "could not register dual_role instance\n");

		goto unreg_psy;

		goto put_psy;

	} else {

		pd->dual_role->drv_data = pd;

	}
@@ -3045,13 +3040,18 @@ struct usbpd *usbpd_create(struct device *parent) 
	INIT_LIST_HEAD(&pd->svid_handlers);

	init_completion(&pd->swap_complete);



	pd->psy_nb.notifier_call = psy_changed;

	ret = power_supply_reg_notifier(&pd->psy_nb);

	if (ret)

		goto del_inst;



	/* force read initial power_supply values */

	psy_changed(&pd->psy_nb, PSY_EVENT_PROP_CHANGED, pd->usb_psy);



	return pd;



unreg_psy:

	power_supply_unreg_notifier(&pd->psy_nb);

del_inst:

	list_del(&pd->instance);

put_psy:

	power_supply_put(pd->usb_psy);

destroy_wq: