[PATCH 10/13] staging: most: destroy cdev by channel disconnect

[Christian Gromm]

From: Andrey Shvetsov <andrey.shvet...@k2l.de>

Currently, when the channel disappears whereas the character device is
open by an application, the character device will be destroyed only
after the application closes the character device.

When the channel appears again before the application closes the
channel, the channel cannot be linked to the character device with the
same name.

This patch changes the described behavior and destroys the character
device by the disconnecting the channel from the AIM.

Signed-off-by: Andrey Shvetsov <andrey.shvet...@k2l.de>
Signed-off-by: Christian Gromm <christian.gr...@microchip.com>
---
 drivers/staging/most/aim-cdev/cdev.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/most/aim-cdev/cdev.c 
b/drivers/staging/most/aim-cdev/cdev.c
index 7f51024dc5eb..1e5cbc893496 100644
--- a/drivers/staging/most/aim-cdev/cdev.c
+++ b/drivers/staging/most/aim-cdev/cdev.c
@@ -99,11 +99,16 @@ static void destroy_cdev(struct aim_channel *c)
 
        device_destroy(aim_class, c->devno);
        cdev_del(&c->cdev);
-       kfifo_free(&c->fifo);
        spin_lock_irqsave(&ch_list_lock, flags);
        list_del(&c->list);
        spin_unlock_irqrestore(&ch_list_lock, flags);
+}
+
+static void destroy_channel(struct aim_channel *c)
+{
        ida_simple_remove(&minor_id, MINOR(c->devno));
+       kfifo_free(&c->fifo);
+       kfree(c);
 }
 
 /**
@@ -170,9 +175,8 @@ static int aim_close(struct inode *inode, struct file *filp)
                stop_channel(c);
                mutex_unlock(&c->io_mutex);
        } else {
-               destroy_cdev(c);
                mutex_unlock(&c->io_mutex);
-               kfree(c);
+               destroy_channel(c);
        }
        return 0;
 }
@@ -337,14 +341,14 @@ static int aim_disconnect_channel(struct most_interface 
*iface, int channel_id)
        spin_lock(&c->unlink);
        c->dev = NULL;
        spin_unlock(&c->unlink);
+       destroy_cdev(c);
        if (c->access_ref) {
                stop_channel(c);
                wake_up_interruptible(&c->wq);
                mutex_unlock(&c->io_mutex);
        } else {
-               destroy_cdev(c);
                mutex_unlock(&c->io_mutex);
-               kfree(c);
+               destroy_channel(c);
        }
        return 0;
 }
@@ -546,7 +550,7 @@ static void __exit mod_exit(void)
 
        list_for_each_entry_safe(c, tmp, &channel_list, list) {
                destroy_cdev(c);
-               kfree(c);
+               destroy_channel(c);
        }
        class_destroy(aim_class);
        unregister_chrdev_region(aim_devno, 1);
-- 
2.11.0

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