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Commit 795ce218 authored by Christian Gromm's avatar Christian Gromm Committed by Greg Kroah-Hartman
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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
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+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");