diff options
Diffstat (limited to 'drivers/usb/class/usbtmc.c')
| -rw-r--r-- | drivers/usb/class/usbtmc.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c index b09a527f734..0c9df97f677 100644 --- a/drivers/usb/class/usbtmc.c +++ b/drivers/usb/class/usbtmc.c @@ -86,6 +86,8 @@ struct usbtmc_device_data { bool TermCharEnabled; bool auto_abort; + bool zombie; /* fd of disconnected device */ + struct usbtmc_dev_capabilities capabilities; struct kref kref; struct mutex io_mutex; /* only one i/o function running at a time */ @@ -384,6 +386,10 @@ static ssize_t usbtmc_read(struct file *filp, char __user *buf, return -ENOMEM; mutex_lock(&data->io_mutex); + if (data->zombie) { + retval = -ENODEV; + goto exit; + } remaining = count; done = 0; @@ -496,6 +502,10 @@ static ssize_t usbtmc_write(struct file *filp, const char __user *buf, return -ENOMEM; mutex_lock(&data->io_mutex); + if (data->zombie) { + retval = -ENODEV; + goto exit; + } remaining = count; done = 0; @@ -925,6 +935,10 @@ static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg) data = file->private_data; mutex_lock(&data->io_mutex); + if (data->zombie) { + retval = -ENODEV; + goto skip_io_on_zombie; + } switch (cmd) { case USBTMC_IOCTL_CLEAR_OUT_HALT: @@ -952,6 +966,7 @@ static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg) break; } +skip_io_on_zombie: mutex_unlock(&data->io_mutex); return retval; } @@ -995,6 +1010,7 @@ static int usbtmc_probe(struct usb_interface *intf, usb_set_intfdata(intf, data); kref_init(&data->kref); mutex_init(&data->io_mutex); + data->zombie = 0; /* Initialize USBTMC bTag and other fields */ data->bTag = 1; @@ -1065,6 +1081,9 @@ static void usbtmc_disconnect(struct usb_interface *intf) usb_deregister_dev(intf, &usbtmc_class); sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp); sysfs_remove_group(&intf->dev.kobj, &data_attr_grp); + mutex_lock(&data->io_mutex); + data->zombie = 1; + mutex_unlock(&data->io_mutex); kref_put(&data->kref, usbtmc_delete); } |