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V4L/DVB (9655): radio-mr800: fix unplug 

This patch fixes problems(kernel oopses) with unplug of device while
it's working.
Patch adds disconnect_lock mutex, changes usb_amradio_close and
usb_amradio_disconnect functions and adds a lot of safety checks.

Signed-off-by: Alexey Klimov <klimov.linux@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Alexey Klimov 2008-11-19 00:36:29 -03:00 committed by Mauro Carvalho Chehab
parent c7abfb47c9
commit 3480130a50
1 changed files with 54 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

62
drivers/media/radio/radio-mr800.c
View File

@ -141,6 +141,7 @@ struct amradio_device {
unsigned char *buffer;
struct mutex lock; /* buffer locking */
struct mutex disconnect_lock;
int curfreq;
int stereo;
int users;
@ -207,6 +208,10 @@ static int amradio_stop(struct amradio_device *radio)
int retval;
int size;
/* safety check */
if (radio->removed)
return -EIO;
mutex_lock(&radio->lock);
radio->buffer[0] = 0x00;
@ -240,6 +245,10 @@ static int amradio_setfreq(struct amradio_device *radio, int freq)
int size;
unsigned short freq_send = 0x13 + (freq >> 3) / 25;
/* safety check */
if (radio->removed)
return -EIO;
mutex_lock(&radio->lock);
radio->buffer[0] = 0x00;
@ -293,18 +302,16 @@ static void usb_amradio_disconnect(struct usb_interface *intf)
{
struct amradio_device *radio = usb_get_intfdata(intf);
mutex_lock(&radio->disconnect_lock);
radio->removed = 1;
usb_set_intfdata(intf, NULL);
if (radio) {
if (radio->users == 0) {
video_unregister_device(radio->videodev);
radio->videodev = NULL;
if (radio->users) {
kfree(radio->buffer);
kfree(radio);
} else {
radio->removed = 1;
}
kfree(radio->buffer);
kfree(radio);
}
mutex_unlock(&radio->disconnect_lock);
}
/* vidioc_querycap - query device capabilities */
@ -325,6 +332,10 @@ static int vidioc_g_tuner(struct file *file, void *priv,
{
struct amradio_device *radio = video_get_drvdata(video_devdata(file));
/* safety check */
if (radio->removed)
return -EIO;
if (v->index > 0)
return -EINVAL;
@ -351,6 +362,12 @@ static int vidioc_g_tuner(struct file *file, void *priv,
static int vidioc_s_tuner(struct file *file, void *priv,
struct v4l2_tuner *v)
{
struct amradio_device *radio = video_get_drvdata(video_devdata(file));
/* safety check */
if (radio->removed)
return -EIO;
if (v->index > 0)
return -EINVAL;
return 0;
@ -362,6 +379,10 @@ static int vidioc_s_frequency(struct file *file, void *priv,
{
struct amradio_device *radio = video_get_drvdata(video_devdata(file));
/* safety check */
if (radio->removed)
return -EIO;
radio->curfreq = f->frequency;
if (amradio_setfreq(radio, radio->curfreq) < 0)
amradio_dev_warn(&radio->videodev->dev,
@ -375,6 +396,10 @@ static int vidioc_g_frequency(struct file *file, void *priv,
{
struct amradio_device *radio = video_get_drvdata(video_devdata(file));
/* safety check */
if (radio->removed)
return -EIO;
f->type = V4L2_TUNER_RADIO;
f->frequency = radio->curfreq;
return 0;
@ -401,6 +426,10 @@ static int vidioc_g_ctrl(struct file *file, void *priv,
{
struct amradio_device *radio = video_get_drvdata(video_devdata(file));
/* safety check */
if (radio->removed)
return -EIO;
switch (ctrl->id) {
case V4L2_CID_AUDIO_MUTE:
ctrl->value = radio->muted;
@ -415,6 +444,10 @@ static int vidioc_s_ctrl(struct file *file, void *priv,
{
struct amradio_device *radio = video_get_drvdata(video_devdata(file));
/* safety check */
if (radio->removed)
return -EIO;
switch (ctrl->id) {
case V4L2_CID_AUDIO_MUTE:
if (ctrl->value) {
@ -500,14 +533,26 @@ static int usb_amradio_open(struct inode *inode, struct file *file)
static int usb_amradio_close(struct inode *inode, struct file *file)
{
struct amradio_device *radio = video_get_drvdata(video_devdata(file));
int retval;
if (!radio)
return -ENODEV;
mutex_lock(&radio->disconnect_lock);
radio->users = 0;
if (radio->removed) {
video_unregister_device(radio->videodev);
kfree(radio->buffer);
kfree(radio);
} else {
retval = amradio_stop(radio);
if (retval < 0)
amradio_dev_warn(&radio->videodev->dev,
"amradio_stop failed\n");
}
mutex_unlock(&radio->disconnect_lock);
return 0;
}
@ -607,6 +652,7 @@ static int usb_amradio_probe(struct usb_interface *intf,
radio->usbdev = interface_to_usbdev(intf);
radio->curfreq = 95.16 * FREQ_MUL;
mutex_init(&radio->disconnect_lock);
mutex_init(&radio->lock);
video_set_drvdata(radio->videodev, radio);