diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/usb-skeleton.c | 42 |
1 files changed, 37 insertions, 5 deletions
diff --git a/drivers/usb/usb-skeleton.c b/drivers/usb/usb-skeleton.c index 1b1e669dff9a..59973aecd968 100644 --- a/drivers/usb/usb-skeleton.c +++ b/drivers/usb/usb-skeleton.c @@ -57,6 +57,7 @@ struct usb_skel { __u8 bulk_in_endpointAddr; /* the address of the bulk in endpoint */ __u8 bulk_out_endpointAddr; /* the address of the bulk out endpoint */ int errors; /* the last request tanked */ + int open_count; /* count the number of openers */ spinlock_t err_lock; /* lock for errors */ struct kref kref; struct mutex io_mutex; /* synchronize I/O with disconnect */ @@ -101,12 +102,26 @@ static int skel_open(struct inode *inode, struct file *file) /* increment our usage count for the device */ kref_get(&dev->kref); - /* prevent the device from being autosuspended */ - retval = usb_autopm_get_interface(interface); - if (retval) { + /* lock the device to allow correctly handling errors + * in resumption */ + mutex_lock(&dev->io_mutex); + + if (!dev->open_count++) { + retval = usb_autopm_get_interface(interface); + if (retval) { + dev->open_count--; + mutex_unlock(&dev->io_mutex); + kref_put(&dev->kref, skel_delete); + goto exit; + } + } /* else { //uncomment this block if you want exclusive open + retval = -EBUSY; + dev->open_count--; + mutex_unlock(&dev->io_mutex); kref_put(&dev->kref, skel_delete); goto exit; - } + } */ + /* prevent the device from being autosuspended */ /* save our object in the file's private structure */ file->private_data = dev; @@ -125,7 +140,7 @@ static int skel_release(struct inode *inode, struct file *file) /* allow the device to be autosuspended */ mutex_lock(&dev->io_mutex); - if (dev->interface) + if (!--dev->open_count && dev->interface) usb_autopm_put_interface(dev->interface); mutex_unlock(&dev->io_mutex); @@ -437,10 +452,27 @@ static void skel_draw_down(struct usb_skel *dev) usb_kill_anchored_urbs(&dev->submitted); } +static int skel_suspend(struct usb_interface *intf, pm_message_t message) +{ + struct usb_skel *dev = usb_get_intfdata(intf); + + if (!dev) + return 0; + skel_draw_down(dev); + return 0; +} + +static int skel_resume (struct usb_interface *intf) +{ + return 0; +} + static struct usb_driver skel_driver = { .name = "skeleton", .probe = skel_probe, .disconnect = skel_disconnect, + .suspend = skel_suspend, + .resume = skel_resume, .id_table = skel_table, .supports_autosuspend = 1, }; |