From 03dea86de2243d5b3932604b799be26efeff010d Mon Sep 17 00:00:00 2001 From: Tobias Lorenz Date: Tue, 22 Apr 2008 14:46:11 -0300 Subject: [PATCH] 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 Signed-off-by: Mauro Carvalho Chehab --- drivers/media/radio/radio-si470x.c | 57 ++++++++++++++++++++++++++++++++------ 1 file changed, 48 insertions(+), 9 deletions(-) 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 * Version 1.0.7 * - usb autosuspend support + * - unplugging fixed * * ToDo: * - add seeking support @@ -97,10 +98,10 @@ /* driver definitions */ #define DRIVER_AUTHOR "Tobias Lorenz " #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 @@ struct si470x_device { /* driver management */ unsigned int users; + unsigned char disconnected; /* Silabs internal registers (0..15) */ unsigned short registers[RADIO_REGISTER_NUM]; @@ -440,6 +442,12 @@ struct si470x_device { /* + * 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 @@ static int si470x_get_rds_registers(struct si470x_device *radio) 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 @@ static void si470x_work(struct work_struct *work) 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_open(struct inode *inode, struct file *file) 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 @@ static int si470x_fops_release(struct inode *inode, struct file *file) 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 @@ static int si470x_vidioc_g_ctrl(struct file *file, void *priv, { 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 @@ static int si470x_vidioc_s_ctrl(struct file *file, void *priv, 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 @@ static int si470x_vidioc_g_tuner(struct file *file, void *priv, 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 @@ static int si470x_vidioc_s_tuner(struct file *file, void *priv, 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 @@ static int si470x_vidioc_g_frequency(struct file *file, void *priv, { 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 @@ static int si470x_vidioc_s_frequency(struct file *file, void *priv, 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 @@ static void si470x_usb_driver_disconnect(struct usb_interface *intf) { 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); } -- 2.7.4