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Commit 307ba6dd authored by David Vrabel's avatar David Vrabel
Browse files

uwb: don't unbind the radio controller driver when resetting 



Use pre_reset and post_reset methods to avoid unbinding the radio
controller driver after a uwb_rc_reset_all() call.  This avoids a
deadlock in uwb_rc_rm() when waiting for the uwb event thread to stop.

Signed-off-by: default avatarDavid Vrabel <david.vrabel@csr.com>
parent fec1a593

drivers/uwb/hwa-rc.c

+21 −1
Original line number Diff line number Diff line
@@ -881,6 +881,24 @@ static void hwarc_disconnect(struct usb_interface *iface) 
	uwb_rc_put(uwb_rc);	/* when creating the device, refcount = 1 */

}



static int hwarc_pre_reset(struct usb_interface *iface)

{

	struct hwarc *hwarc = usb_get_intfdata(iface);

	struct uwb_rc *uwb_rc = hwarc->uwb_rc;



	uwb_rc_pre_reset(uwb_rc);

	return 0;

}



static int hwarc_post_reset(struct usb_interface *iface)

{

	struct hwarc *hwarc = usb_get_intfdata(iface);

	struct uwb_rc *uwb_rc = hwarc->uwb_rc;



	uwb_rc_post_reset(uwb_rc);

	return 0;

}



/** USB device ID's that we handle */

static struct usb_device_id hwarc_id_table[] = {

	/* D-Link DUB-1210 */
@@ -897,9 +915,11 @@ MODULE_DEVICE_TABLE(usb, hwarc_id_table); 


static struct usb_driver hwarc_driver = {

	.name =		"hwa-rc",

	.id_table =	hwarc_id_table,

	.probe =	hwarc_probe,

	.disconnect =	hwarc_disconnect,

	.id_table =	hwarc_id_table,

	.pre_reset =    hwarc_pre_reset,

	.post_reset =   hwarc_post_reset,

};



static int __init hwarc_driver_init(void)

drivers/uwb/reset.c

+41 −8
Original line number Diff line number Diff line
@@ -323,17 +323,16 @@ int uwbd_msg_handle_reset(struct uwb_event *evt) 
	struct uwb_rc *rc = evt->rc;

	int ret;



	/* Need to prevent the RC hardware module going away while in

	   the rc->reset() call. */

	if (!try_module_get(rc->owner))

		return 0;



	dev_info(&rc->uwb_dev.dev, "resetting radio controller\n");

	ret = rc->reset(rc);

	if (ret)

	if (ret) {

		dev_err(&rc->uwb_dev.dev, "failed to reset hardware: %d\n", ret);



	module_put(rc->owner);

		goto error;

	}

	return 0;

error:

	/* Nothing can be done except try the reset again. */

	uwb_rc_reset_all(rc);

	return ret;

}
@@ -360,3 +359,37 @@ void uwb_rc_reset_all(struct uwb_rc *rc) 
	uwbd_event_queue(evt);

}

EXPORT_SYMBOL_GPL(uwb_rc_reset_all);



void uwb_rc_pre_reset(struct uwb_rc *rc)

{

	rc->stop(rc);

	uwbd_flush(rc);



	mutex_lock(&rc->uwb_dev.mutex);

	rc->beaconing = -1;

	rc->scanning = -1;

	mutex_unlock(&rc->uwb_dev.mutex);



	uwb_rsv_remove_all(rc);

}

EXPORT_SYMBOL_GPL(uwb_rc_pre_reset);



void uwb_rc_post_reset(struct uwb_rc *rc)

{

	int ret;



	ret = rc->start(rc);

	if (ret)

		goto error;

	ret = uwb_rc_mac_addr_set(rc, &rc->uwb_dev.mac_addr);

	if (ret)

		goto error;

	ret = uwb_rc_dev_addr_set(rc, &rc->uwb_dev.dev_addr);

	if (ret)

		goto error;

	return;

error:

	/* Nothing can be done except try the reset again. */

	uwb_rc_reset_all(rc);

}

EXPORT_SYMBOL_GPL(uwb_rc_post_reset);

drivers/uwb/rsv.c

+20 −9
Original line number Diff line number Diff line
@@ -659,6 +659,25 @@ static void uwb_rsv_timer(unsigned long arg) 
	uwb_rsv_sched_update(rsv->rc);

}



/**

 * uwb_rsv_remove_all - remove all reservations

 * @rc: the radio controller

 *

 * A DRP IE update is not done.

 */

void uwb_rsv_remove_all(struct uwb_rc *rc)

{

	struct uwb_rsv *rsv, *t;



	mutex_lock(&rc->rsvs_mutex);

	list_for_each_entry_safe(rsv, t, &rc->reservations, rc_node) {

		uwb_rsv_remove(rsv);

	}

	mutex_unlock(&rc->rsvs_mutex);



	cancel_work_sync(&rc->rsv_update_work);

}



void uwb_rsv_init(struct uwb_rc *rc)

{

	INIT_LIST_HEAD(&rc->reservations);
@@ -682,14 +701,6 @@ int uwb_rsv_setup(struct uwb_rc *rc) 


void uwb_rsv_cleanup(struct uwb_rc *rc)

{

	struct uwb_rsv *rsv, *t;



	mutex_lock(&rc->rsvs_mutex);

	list_for_each_entry_safe(rsv, t, &rc->reservations, rc_node) {

		uwb_rsv_remove(rsv);

	}

	mutex_unlock(&rc->rsvs_mutex);



	cancel_work_sync(&rc->rsv_update_work);

	uwb_rsv_remove_all(rc);

	destroy_workqueue(rc->rsv_workq);

}

drivers/uwb/umc-bus.c

+43 −19
Original line number Diff line number Diff line
@@ -11,23 +11,48 @@ 
#include <linux/uwb/umc.h>

#include <linux/pci.h>



static int umc_bus_unbind_helper(struct device *dev, void *data)

static int umc_bus_pre_reset_helper(struct device *dev, void *data)

{

	struct device *parent = data;

	int ret = 0;



	if (dev->driver) {

		struct umc_dev *umc = to_umc_dev(dev);

		struct umc_driver *umc_drv = to_umc_driver(dev->driver);



	if (dev->parent == parent && dev->driver)

		if (umc_drv->pre_reset)

			ret = umc_drv->pre_reset(umc);

		else

			device_release_driver(dev);

	return 0;

	}

	return ret;

}



static int umc_bus_post_reset_helper(struct device *dev, void *data)

{

	int ret = 0;



	if (dev->driver) {

		struct umc_dev *umc = to_umc_dev(dev);

		struct umc_driver *umc_drv = to_umc_driver(dev->driver);



		if (umc_drv->post_reset)

			ret = umc_drv->post_reset(umc);

	} else

		ret = device_attach(dev);



	return ret;

}



/**

 * umc_controller_reset - reset the whole UMC controller

 * @umc: the UMC device for the radio controller.

 *

 * Drivers will be unbound from all UMC devices belonging to the

 * controller and then the radio controller will be rebound.  The

 * radio controller is expected to do a full hardware reset when it is

 * probed.

 * Drivers or all capabilities of the controller will have their

 * pre_reset methods called or be unbound from their device.  Then all

 * post_reset methods will be called or the drivers will be rebound.

 *

 * Radio controllers must provide pre_reset and post_reset methods and

 * reset the hardware in their start method.

 *

 * If this is called while a probe() or remove() is in progress it

 * will return -EAGAIN and not perform the reset.
@@ -35,14 +60,13 @@ static int umc_bus_unbind_helper(struct device *dev, void *data) 
int umc_controller_reset(struct umc_dev *umc)

{

	struct device *parent = umc->dev.parent;

	int ret;

	int ret = 0;



	if(down_trylock(&parent->sem))

		return -EAGAIN;

	bus_for_each_dev(&umc_bus_type, NULL, parent, umc_bus_unbind_helper);

	ret = device_attach(&umc->dev);

	if (ret == 1)

		ret = 0;

	ret = device_for_each_child(parent, parent, umc_bus_pre_reset_helper);

	if (ret >= 0)

		device_for_each_child(parent, parent, umc_bus_post_reset_helper);

	up(&parent->sem);



	return ret;
@@ -75,10 +99,10 @@ static int umc_bus_rescan_helper(struct device *dev, void *data) 
	if (!dev->driver)

		ret = device_attach(dev);



	return ret < 0 ? ret : 0;

	return ret;

}



static void umc_bus_rescan(void)

static void umc_bus_rescan(struct device *parent)

{

	int err;
@@ -86,7 +110,7 @@ static void umc_bus_rescan(void) 
	 * We can't use bus_rescan_devices() here as it deadlocks when

	 * it tries to retake the dev->parent semaphore.

	 */

	err = bus_for_each_dev(&umc_bus_type, NULL, NULL, umc_bus_rescan_helper);

	err = device_for_each_child(parent, NULL, umc_bus_rescan_helper);

	if (err < 0)

		printk(KERN_WARNING "%s: rescan of bus failed: %d\n",

		       KBUILD_MODNAME, err);
@@ -120,7 +144,7 @@ static int umc_device_probe(struct device *dev) 
	if (err)

		put_device(dev);

	else

		umc_bus_rescan();

		umc_bus_rescan(dev->parent);



	return err;

}

drivers/uwb/uwb-internal.h

+1 −0
Original line number Diff line number Diff line
@@ -248,6 +248,7 @@ extern struct device_attribute dev_attr_scan; 
void uwb_rsv_init(struct uwb_rc *rc);

int uwb_rsv_setup(struct uwb_rc *rc);

void uwb_rsv_cleanup(struct uwb_rc *rc);

void uwb_rsv_remove_all(struct uwb_rc *rc);



void uwb_rsv_set_state(struct uwb_rsv *rsv, enum uwb_rsv_state new_state);

void uwb_rsv_remove(struct uwb_rsv *rsv);