staging: most: i2c: shorten lifetime of IRQ handler

Currently the IRQ handler used for the rx channel lives between the
functions i2c_probe and i2c_remove. This patch shortens the lifetime
and keeps the handler alive only between the functions configure_channel
and poison_channel.

Signed-off-by: Christian Gromm <christian.gromm@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/most/i2c/i2c.c b/drivers/staging/most/i2c/i2c.c
index 8ec660bd299023ff6fa4ae051019e9bbd0c0fa3d..b382f094a901167631e43305d71a04ab4d9f9767 100644 (file)
--- a/drivers/staging/most/i2c/i2c.c
+++ b/drivers/staging/most/i2c/i2c.c
@@ -56,6 +56,8 @@ struct hdm_i2c {
 
 #define to_hdm(iface) container_of(iface, struct hdm_i2c, most_iface)
 
+static irqreturn_t most_irq_handler(int, void *);
+
 /**
  * configure_channel - called from MOST core to configure a channel
  * @iface: interface the channel belongs to
@@ -71,6 +73,7 @@ static int configure_channel(struct most_interface *most_iface,
                             int ch_idx,
                             struct most_channel_config *channel_config)
 {
+       int ret;
        struct hdm_i2c *dev = to_hdm(most_iface);
 
        BUG_ON(ch_idx < 0 || ch_idx >= NUM_CHANNELS);
@@ -86,7 +89,21 @@ static int configure_channel(struct most_interface *most_iface,
                return -EPERM;
        }
 
+       if (channel_config->direction == MOST_CH_RX) {
+               dev->polling_mode = polling_req || dev->client->irq <= 0;
+               if (!dev->polling_mode) {
+                       pr_info("Requesting IRQ: %d\n", dev->client->irq);
+                       ret = request_irq(dev->client->irq, most_irq_handler, 0,
+                                         dev->client->name, dev);
+                       if (ret) {
+                               pr_info("IRQ request failed: %d, falling back to polling\n",
+                                       ret);
+                               dev->polling_mode = true;
+                       }
+               }
+       }
        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));
        }
@@ -160,6 +177,10 @@ static int poison_channel(struct most_interface *most_iface,
        dev->is_open[ch_idx] = false;
 
        if (ch_idx == CH_RX) {
+               if (!dev->polling_mode)
+                       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);
@@ -347,21 +368,6 @@ static int i2c_probe(struct i2c_client *client, const struct i2c_device_id *id)
                return ret;
        }
 
-       dev->polling_mode = polling_req || client->irq <= 0;
-       if (!dev->polling_mode) {
-               pr_info("Requesting IRQ: %d\n", client->irq);
-               ret = request_irq(client->irq, most_irq_handler, 0,
-                                 client->name, dev);
-               if (ret) {
-                       pr_info("IRQ request failed: %d, falling back to polling\n",
-                               ret);
-                       dev->polling_mode = true;
-               }
-       }
-
-       if (dev->polling_mode)
-               pr_info("Using polling at rate: %d times/sec\n", scan_rate);
-
        return 0;
 }
 
@@ -377,11 +383,7 @@ static int i2c_remove(struct i2c_client *client)
 {
        struct hdm_i2c *dev = i2c_get_clientdata(client);
 
-       if (!dev->polling_mode)
-               free_irq(client->irq, dev);
-
        most_deregister_interface(&dev->most_iface);
-       cancel_delayed_work_sync(&dev->rx.dwork);
        kfree(dev);
 
        return 0;