V4L/DVB (7401): radio-si470x: unplugging fixed
This patch fixes several kernel oops, when unplugging device while it is in
use:
Basically the patch delays freeing of the internal variables in
si470x_usb_driver_disconnect, until the the last user closed the device in
si470x_fops_release. This was implemented a while ago with the help of Oliver
Neukum.
I tested the patch five times (unplugging while in use) without oops coming
from the radio-si470x driver anymore. A remaining oops was coming from the
usbaudio driver, but this is someone else task. Hopefully this fixed all
unplugging issues.
Signed-off-by: Tobias Lorenz <tobias.lorenz@gmx.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/radio/radio-si470x.c b/drivers/media/radio/radio-si470x.c
index 649f14d..4ad88ee 100644
--- a/drivers/media/radio/radio-si470x.c
+++ b/drivers/media/radio/radio-si470x.c
@@ -85,6 +85,7 @@
* Oliver Neukum <oliver@neukum.org>
* Version 1.0.7
* - usb autosuspend support
+ * - unplugging fixed
*
* ToDo:
* - add seeking support
@@ -97,10 +98,10 @@
/* driver definitions */
#define DRIVER_AUTHOR "Tobias Lorenz <tobias.lorenz@gmx.net>"
#define DRIVER_NAME "radio-si470x"
-#define DRIVER_KERNEL_VERSION KERNEL_VERSION(1, 0, 6)
+#define DRIVER_KERNEL_VERSION KERNEL_VERSION(1, 0, 7)
#define DRIVER_CARD "Silicon Labs Si470x FM Radio Receiver"
#define DRIVER_DESC "USB radio driver for Si470x FM Radio Receivers"
-#define DRIVER_VERSION "1.0.6"
+#define DRIVER_VERSION "1.0.7"
/* kernel includes */
@@ -424,6 +425,7 @@
/* driver management */
unsigned int users;
+ unsigned char disconnected;
/* Silabs internal registers (0..15) */
unsigned short registers[RADIO_REGISTER_NUM];
@@ -440,6 +442,12 @@
/*
+ * Lock to prevent kfree of data before all users have releases the device.
+ */
+static DEFINE_MUTEX(open_close_lock);
+
+
+/*
* The frequency is set in units of 62.5 Hz when using V4L2_TUNER_CAP_LOW,
* 62.5 kHz otherwise.
* The tuner is able to have a channel spacing of 50, 100 or 200 kHz.
@@ -577,7 +585,7 @@
usb_rcvintpipe(radio->usbdev, 1),
(void *) &buf, sizeof(buf), &size, usb_timeout);
if (size != sizeof(buf))
- printk(KERN_WARNING DRIVER_NAME ": si470x_get_rds_register: "
+ printk(KERN_WARNING DRIVER_NAME ": si470x_get_rds_registers: "
"return size differs: %d != %zu\n", size, sizeof(buf));
if (retval < 0)
printk(KERN_WARNING DRIVER_NAME ": si470x_get_rds_registers: "
@@ -875,6 +883,8 @@
struct si470x_device *radio = container_of(work, struct si470x_device,
work.work);
+ if (radio->disconnected)
+ return;
if ((radio->registers[SYSCONFIG1] & SYSCONFIG1_RDS) == 0)
return;
@@ -1001,13 +1011,21 @@
static int si470x_fops_release(struct inode *inode, struct file *file)
{
struct si470x_device *radio = video_get_drvdata(video_devdata(file));
- int retval;
+ int retval = 0;
if (!radio)
return -ENODEV;
+ mutex_lock(&open_close_lock);
radio->users--;
if (radio->users == 0) {
+ if (radio->disconnected) {
+ video_unregister_device(radio->videodev);
+ kfree(radio->buffer);
+ kfree(radio);
+ goto done;
+ }
+
/* stop rds reception */
cancel_delayed_work_sync(&radio->work);
@@ -1016,10 +1034,11 @@
retval = si470x_stop(radio);
usb_autopm_put_interface(radio->intf);
- return retval;
}
- return 0;
+done:
+ mutex_unlock(&open_close_lock);
+ return retval;
}
@@ -1157,6 +1176,9 @@
{
struct si470x_device *radio = video_get_drvdata(video_devdata(file));
+ if (radio->disconnected)
+ return -EIO;
+
switch (ctrl->id) {
case V4L2_CID_AUDIO_VOLUME:
ctrl->value = radio->registers[SYSCONFIG2] &
@@ -1181,6 +1203,9 @@
struct si470x_device *radio = video_get_drvdata(video_devdata(file));
int retval;
+ if (radio->disconnected)
+ return -EIO;
+
switch (ctrl->id) {
case V4L2_CID_AUDIO_VOLUME:
radio->registers[SYSCONFIG2] &= ~SYSCONFIG2_VOLUME;
@@ -1243,6 +1268,8 @@
struct si470x_device *radio = video_get_drvdata(video_devdata(file));
int retval;
+ if (radio->disconnected)
+ return -EIO;
if (tuner->index > 0)
return -EINVAL;
@@ -1299,6 +1326,8 @@
struct si470x_device *radio = video_get_drvdata(video_devdata(file));
int retval;
+ if (radio->disconnected)
+ return -EIO;
if (tuner->index > 0)
return -EINVAL;
@@ -1324,6 +1353,9 @@
{
struct si470x_device *radio = video_get_drvdata(video_devdata(file));
+ if (radio->disconnected)
+ return -EIO;
+
freq->type = V4L2_TUNER_RADIO;
freq->frequency = si470x_get_freq(radio);
@@ -1340,6 +1372,8 @@
struct si470x_device *radio = video_get_drvdata(video_devdata(file));
int retval;
+ if (radio->disconnected)
+ return -EIO;
if (freq->type != V4L2_TUNER_RADIO)
return -EINVAL;
@@ -1510,11 +1544,16 @@
{
struct si470x_device *radio = usb_get_intfdata(intf);
+ mutex_lock(&open_close_lock);
+ radio->disconnected = 1;
cancel_delayed_work_sync(&radio->work);
usb_set_intfdata(intf, NULL);
- video_unregister_device(radio->videodev);
- kfree(radio->buffer);
- kfree(radio);
+ if (radio->users == 0) {
+ video_unregister_device(radio->videodev);
+ kfree(radio->buffer);
+ kfree(radio);
+ }
+ mutex_unlock(&open_close_lock);
}