hollalinux
/
linux-sg2042
mirror of https://github.com/sophgo/linux-riscv.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

V4L/DVB (9086): gspca: Use a kref to avoid potentialy blocking forever in disconnect. 

Signed-off-by: Frank Zago <frank@zago.net>
Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Frank Zago 2008-09-28 08:12:22 -03:00 committed by Mauro Carvalho Chehab
parent 6c49da7f16
commit 6b060ffea0
2 changed files with 28 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

39
drivers/media/video/gspca/gspca.c
View File

@ -29,6 +29,7 @@
#include <linux/string.h>
#include <linux/pagemap.h>
#include <linux/io.h>
#include <linux/kref.h>
#include <asm/page.h>
#include <linux/uaccess.h>
#include <linux/jiffies.h>
@ -834,6 +835,16 @@ out:
return ret;
}
static void gspca_delete(struct kref *kref)
{
struct gspca_dev *gspca_dev = container_of(kref, struct gspca_dev, kref);
PDEBUG(D_STREAM, "device deleted");
kfree(gspca_dev->usb_buf);
kfree(gspca_dev);
}
static int dev_open(struct inode *inode, struct file *file)
{
struct gspca_dev *gspca_dev;
@ -853,6 +864,10 @@ static int dev_open(struct inode *inode, struct file *file)
goto out;
}
gspca_dev->users++;
/* one more user */
kref_get(&gspca_dev->kref);
file->private_data = gspca_dev;
#ifdef GSPCA_DEBUG
/* activate the v4l2 debug */
@ -895,7 +910,11 @@ static int dev_close(struct inode *inode, struct file *file)
}
file->private_data = NULL;
mutex_unlock(&gspca_dev->queue_lock);
PDEBUG(D_STREAM, "close done");
kref_put(&gspca_dev->kref, gspca_delete);
return 0;
}
@ -1809,6 +1828,7 @@ int gspca_dev_probe(struct usb_interface *intf,
err("couldn't kzalloc gspca struct");
return -EIO;
}
kref_init(&gspca_dev->kref);
gspca_dev->usb_buf = kmalloc(USB_BUF_SZ, GFP_KERNEL);
if (!gspca_dev->usb_buf) {
err("out of memory");
@ -1858,8 +1878,7 @@ int gspca_dev_probe(struct usb_interface *intf,
PDEBUG(D_PROBE, "probe ok");
return 0;
out:
kfree(gspca_dev->usb_buf);
kfree(gspca_dev);
kref_put(&gspca_dev->kref, gspca_delete);
return ret;
}
EXPORT_SYMBOL(gspca_dev_probe);
@ -1874,8 +1893,8 @@ void gspca_disconnect(struct usb_interface *intf)
{
struct gspca_dev *gspca_dev = usb_get_intfdata(intf);
if (!gspca_dev)
return;
usb_set_intfdata(intf, NULL);
gspca_dev->present = 0;
mutex_lock(&gspca_dev->queue_lock);
mutex_lock(&gspca_dev->usb_lock);
@ -1883,16 +1902,12 @@ void gspca_disconnect(struct usb_interface *intf)
destroy_urbs(gspca_dev);
mutex_unlock(&gspca_dev->usb_lock);
mutex_unlock(&gspca_dev->queue_lock);
while (gspca_dev->users != 0) { /* wait until fully closed */
atomic_inc(&gspca_dev->nevent);
wake_up_interruptible(&gspca_dev->wq); /* wake processes */
schedule();
}
/* We don't want people trying to open up the device */
video_unregister_device(&gspca_dev->vdev);
/* Free the memory */
kfree(gspca_dev->usb_buf);
kfree(gspca_dev);
kref_put(&gspca_dev->kref, gspca_delete);
PDEBUG(D_PROBE, "disconnect complete");
}
EXPORT_SYMBOL(gspca_disconnect);

1
drivers/media/video/gspca/gspca.h
View File

@ -121,6 +121,7 @@ struct gspca_dev {
struct video_device vdev; /* !! must be the first item */
struct file_operations fops;
struct usb_device *dev;
struct kref kref;
struct file *capt_file; /* file doing video capture */
struct cam cam; /* device information */