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Commit eb50842c authored by Christian Gromm's avatar Christian Gromm Committed by Greg Kroah-Hartman
Browse files

staging: most: i2c: remove redundant list_mutex 



The elements of the dev->rx.list are consumed in the pending_rx_work and
populated in the function enqueue() that cancels the pending_rx_work.

The function enqueue() and poison_channel() do not race anyway.

Signed-off-by: default avatarAndrey Shvetsov <andrey.shvetsov@k2l.de>
Signed-off-by: default avatarChristian Gromm <christian.gromm@microchip.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 6471c269

drivers/staging/most/i2c/i2c.c

+1 −16
Original line number Diff line number Diff line
@@ -46,7 +46,6 @@ struct hdm_i2c { 
	struct rx {

		struct delayed_work dwork;

		struct list_head list;

		struct mutex list_mutex;

		bool int_disabled;

		unsigned int delay;

	} rx;
@@ -139,9 +138,7 @@ static int enqueue(struct most_interface *most_iface, 
		if (!dev->polling_mode)

			disable_irq(dev->client->irq);

		cancel_delayed_work_sync(&dev->rx.dwork);

		mutex_lock(&dev->rx.list_mutex);

		list_add_tail(&mbo->list, &dev->rx.list);

		mutex_unlock(&dev->rx.list_mutex);

		if (dev->rx.int_disabled || dev->polling_mode)

			pending_rx_work(&dev->rx.dwork.work);

		if (!dev->polling_mode)
@@ -186,19 +183,14 @@ static int poison_channel(struct most_interface *most_iface, 
			free_irq(dev->client->irq, dev);

		cancel_delayed_work_sync(&dev->rx.dwork);



		mutex_lock(&dev->rx.list_mutex);

		while (!list_empty(&dev->rx.list)) {

			mbo = list_first_mbo(&dev->rx.list);

			list_del(&mbo->list);

			mutex_unlock(&dev->rx.list_mutex);



			mbo->processed_length = 0;

			mbo->status = MBO_E_CLOSE;

			mbo->complete(mbo);



			mutex_lock(&dev->rx.list_mutex);

		}

		mutex_unlock(&dev->rx.list_mutex);

	}



	return 0;
@@ -231,10 +223,8 @@ static void do_rx_work(struct hdm_i2c *dev) 
		return;

	}



	mutex_lock(&dev->rx.list_mutex);

	mbo = list_first_mbo(&dev->rx.list);

	list_del(&mbo->list);

	mutex_unlock(&dev->rx.list_mutex);



	mbo->processed_length = min(data_size, mbo->buffer_length);

	memcpy(mbo->virt_address, msg, mbo->processed_length);
@@ -251,12 +241,8 @@ static void do_rx_work(struct hdm_i2c *dev) 
static void pending_rx_work(struct work_struct *work)

{

	struct hdm_i2c *dev = container_of(work, struct hdm_i2c, rx.dwork.work);

	bool empty;



	mutex_lock(&dev->rx.list_mutex);

	empty = list_empty(&dev->rx.list);

	mutex_unlock(&dev->rx.list_mutex);

	if (empty)

	if (list_empty(&dev->rx.list))

		return;



	do_rx_work(dev);
@@ -340,7 +326,6 @@ static int i2c_probe(struct i2c_client *client, const struct i2c_device_id *id) 
	dev->most_iface.poison_channel = poison_channel;



	INIT_LIST_HEAD(&dev->rx.list);

	mutex_init(&dev->rx.list_mutex);



	INIT_DELAYED_WORK(&dev->rx.dwork, pending_rx_work);