From 795ce21892585ed113fd63a6e06a4fea3ccdaf7b Mon Sep 17 00:00:00 2001 From: Christian Gromm Date: Tue, 8 May 2018 11:44:56 +0200 Subject: 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: Christian Gromm Signed-off-by: Greg Kroah-Hartman --- drivers/staging/most/i2c/i2c.c | 54 ++++++++++++++++-------------------------- 1 file changed, 21 insertions(+), 33 deletions(-) (limited to 'drivers/staging/most') diff --git a/drivers/staging/most/i2c/i2c.c b/drivers/staging/most/i2c/i2c.c index b382f094a901..a993e8e7c740 100644 --- a/drivers/staging/most/i2c/i2c.c +++ b/drivers/staging/most/i2c/i2c.c @@ -11,7 +11,6 @@ #include #include #include -#include #include #include @@ -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); - } - + mutex_lock(&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 "); MODULE_AUTHOR("Andrey Shvetsov "); MODULE_DESCRIPTION("I2C Hardware Dependent Module"); MODULE_LICENSE("GPL"); -- cgit v1.2.3