Commit 795ce218 authored by Christian Gromm's avatar Christian Gromm Committed by Greg Kroah-Hartman
Browse files

staging: most: i2c: do not wait in work function 



This patch removes the function wait_event_interruptible from the
work function to avoid waiting.

Signed-off-by: default avatarChristian Gromm <christian.gromm@microchip.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 0ecbf7fc

drivers/staging/most/i2c/i2c.c

+21 −33
Original line number Diff line number Diff line
@@ -11,7 +11,6 @@ 
#include <linux/module.h>

#include <linux/slab.h>

#include <linux/i2c.h>

#include <linux/sched.h>

#include <linux/interrupt.h>

#include <linux/err.h>
@@ -47,9 +46,9 @@ struct hdm_i2c { 
	struct i2c_client *client;

	struct rx {

		struct delayed_work dwork;

		wait_queue_head_t waitq;

		struct list_head list;

		struct mutex list_mutex;

		bool int_disabled;

	} rx;

	char name[64];

};
@@ -57,6 +56,7 @@ struct hdm_i2c { 
#define to_hdm(iface) container_of(iface, struct hdm_i2c, most_iface)



static irqreturn_t most_irq_handler(int, void *);

static void pending_rx_work(struct work_struct *);



/**

 * configure_channel - called from MOST core to configure a channel
@@ -93,6 +93,7 @@ static int configure_channel(struct most_interface *most_iface, 
		dev->polling_mode = polling_req || dev->client->irq <= 0;

		if (!dev->polling_mode) {

			pr_info("Requesting IRQ: %d\n", dev->client->irq);

			dev->rx.int_disabled = false;

			ret = request_irq(dev->client->irq, most_irq_handler, 0,

					  dev->client->name, dev);

			if (ret) {
@@ -104,8 +105,6 @@ static int configure_channel(struct most_interface *most_iface, 
	}

	if ((channel_config->direction == MOST_CH_RX) && (dev->polling_mode)) {

		pr_info("Using polling at rate: %d times/sec\n", scan_rate);

		schedule_delayed_work(&dev->rx.dwork,

				      msecs_to_jiffies(MSEC_PER_SEC / 4));

	}

	dev->is_open[ch_idx] = true;
@@ -134,10 +133,16 @@ static int enqueue(struct most_interface *most_iface, 


	if (ch_idx == CH_RX) {

		/* RX */

		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);

		wake_up_interruptible(&dev->rx.waitq);

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

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

		if (!dev->polling_mode)

			enable_irq(dev->client->irq);

	} else {

		/* TX */

		ret = i2c_master_send(dev->client, mbo->virt_address,
@@ -194,7 +199,6 @@ static int poison_channel(struct most_interface *most_iface, 
			mutex_lock(&dev->rx.list_mutex);

		}

		mutex_unlock(&dev->rx.list_mutex);

		wake_up_interruptible(&dev->rx.waitq);

	}



	return 0;
@@ -204,7 +208,7 @@ static void do_rx_work(struct hdm_i2c *dev) 
{

	struct mbo *mbo;

	unsigned char msg[MAX_BUF_SIZE_CONTROL];

	int ret, ch_idx = CH_RX;

	int ret;

	u16 pml, data_size;



	/* Read PML (2 bytes) */
@@ -227,29 +231,7 @@ static void do_rx_work(struct hdm_i2c *dev) 
		return;

	}



	for (;;) {

		/* Conditions to wait for: poisoned channel or free buffer

		 * available for reading

		 */

		if (wait_event_interruptible(dev->rx.waitq,

					     !dev->is_open[ch_idx] ||

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

			pr_err("wait_event_interruptible() failed\n");

			return;

		}



		if (!dev->is_open[ch_idx])

			return;



	mutex_lock(&dev->rx.list_mutex);



		/* list may be empty if poison or remove is called */

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

			break;



		mutex_unlock(&dev->rx.list_mutex);

	}



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

	list_del(&mbo->list);

	mutex_unlock(&dev->rx.list_mutex);
@@ -269,6 +251,13 @@ 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)

		return;



	do_rx_work(dev);
@@ -278,6 +267,7 @@ static void pending_rx_work(struct work_struct *work) 
					      msecs_to_jiffies(MSEC_PER_SEC

							       / scan_rate));

	} else {

		dev->rx.int_disabled = false;

		enable_irq(dev->client->irq);

	}

}
@@ -305,7 +295,7 @@ static irqreturn_t most_irq_handler(int irq, void *_dev) 
	struct hdm_i2c *dev = _dev;



	disable_irq_nosync(irq);



	dev->rx.int_disabled = true;

	schedule_delayed_work(&dev->rx.dwork, 0);



	return IRQ_HANDLED;
@@ -354,7 +344,6 @@ static int i2c_probe(struct i2c_client *client, const struct i2c_device_id *id) 


	INIT_LIST_HEAD(&dev->rx.list);

	mutex_init(&dev->rx.list_mutex);

	init_waitqueue_head(&dev->rx.waitq);



	INIT_DELAYED_WORK(&dev->rx.dwork, pending_rx_work);
@@ -407,7 +396,6 @@ static struct i2c_driver i2c_driver = { 


module_i2c_driver(i2c_driver);



MODULE_AUTHOR("Jain Roy Ambi <JainRoy.Ambi@microchip.com>");

MODULE_AUTHOR("Andrey Shvetsov <andrey.shvetsov@k2l.de>");

MODULE_DESCRIPTION("I2C Hardware Dependent Module");

MODULE_LICENSE("GPL");