diff options
Diffstat (limited to 'drivers/usb/core/devio.c')
| -rw-r--r-- | drivers/usb/core/devio.c | 108 |
1 files changed, 101 insertions, 7 deletions
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c index e3696601e43b..3f899552f6e3 100644 --- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -44,10 +44,19 @@ #include "usb.h" +#ifdef CONFIG_PM +#define MAYBE_CAP_SUSPEND USBDEVFS_CAP_SUSPEND +#else +#define MAYBE_CAP_SUSPEND 0 +#endif + #define USB_MAXBUS 64 #define USB_DEVICE_MAX (USB_MAXBUS * 128) #define USB_SG_SIZE 16384 /* split-size for large txs */ +/* Mutual exclusion for ps->list in resume vs. release and remove */ +static DEFINE_MUTEX(usbfs_mutex); + struct usb_dev_state { struct list_head list; /* state list */ struct usb_device *dev; @@ -57,14 +66,17 @@ struct usb_dev_state { struct list_head async_completed; struct list_head memory_list; wait_queue_head_t wait; /* wake up if a request completed */ + wait_queue_head_t wait_for_resume; /* wake up upon runtime resume */ unsigned int discsignr; struct pid *disc_pid; const struct cred *cred; sigval_t disccontext; unsigned long ifclaimed; u32 disabled_bulk_eps; - bool privileges_dropped; unsigned long interface_allowed_mask; + int not_yet_resumed; + bool suspend_allowed; + bool privileges_dropped; }; struct usb_memory { @@ -694,9 +706,7 @@ static void driver_disconnect(struct usb_interface *intf) destroy_async_on_interface(ps, ifnum); } -/* The following routines are merely placeholders. There is no way - * to inform a user task about suspend or resumes. - */ +/* We don't care about suspend/resume of claimed interfaces */ static int driver_suspend(struct usb_interface *intf, pm_message_t msg) { return 0; @@ -707,12 +717,32 @@ static int driver_resume(struct usb_interface *intf) return 0; } +/* The following routines apply to the entire device, not interfaces */ +void usbfs_notify_suspend(struct usb_device *udev) +{ + /* We don't need to handle this */ +} + +void usbfs_notify_resume(struct usb_device *udev) +{ + struct usb_dev_state *ps; + + /* Protect against simultaneous remove or release */ + mutex_lock(&usbfs_mutex); + list_for_each_entry(ps, &udev->filelist, list) { + WRITE_ONCE(ps->not_yet_resumed, 0); + wake_up_all(&ps->wait_for_resume); + } + mutex_unlock(&usbfs_mutex); +} + struct usb_driver usbfs_driver = { .name = "usbfs", .probe = driver_probe, .disconnect = driver_disconnect, .suspend = driver_suspend, .resume = driver_resume, + .supports_autosuspend = 1, }; static int claimintf(struct usb_dev_state *ps, unsigned int ifnum) @@ -991,9 +1021,12 @@ static int usbdev_open(struct inode *inode, struct file *file) INIT_LIST_HEAD(&ps->async_completed); INIT_LIST_HEAD(&ps->memory_list); init_waitqueue_head(&ps->wait); + init_waitqueue_head(&ps->wait_for_resume); ps->disc_pid = get_pid(task_pid(current)); ps->cred = get_current_cred(); smp_wmb(); + + /* Can't race with resume; the device is already active */ list_add_tail(&ps->list, &dev->filelist); file->private_data = ps; usb_unlock_device(dev); @@ -1019,7 +1052,10 @@ static int usbdev_release(struct inode *inode, struct file *file) usb_lock_device(dev); usb_hub_release_all_ports(dev, ps); + /* Protect against simultaneous resume */ + mutex_lock(&usbfs_mutex); list_del_init(&ps->list); + mutex_unlock(&usbfs_mutex); for (ifnum = 0; ps->ifclaimed && ifnum < 8*sizeof(ps->ifclaimed); ifnum++) { @@ -1027,7 +1063,8 @@ static int usbdev_release(struct inode *inode, struct file *file) releaseintf(ps, ifnum); } destroy_all_async(ps); - usb_autosuspend_device(dev); + if (!ps->suspend_allowed) + usb_autosuspend_device(dev); usb_unlock_device(dev); usb_put_dev(dev); put_pid(ps->disc_pid); @@ -1621,7 +1658,8 @@ static int proc_do_submiturb(struct usb_dev_state *ps, struct usbdevfs_urb *uurb if (as->usbm) num_sgs = 0; - u += sizeof(struct async) + sizeof(struct urb) + uurb->buffer_length + + u += sizeof(struct async) + sizeof(struct urb) + + (as->usbm ? 0 : uurb->buffer_length) + num_sgs * sizeof(struct scatterlist); ret = usbfs_increase_memory_usage(u); if (ret) @@ -2273,7 +2311,8 @@ static int proc_get_capabilities(struct usb_dev_state *ps, void __user *arg) caps = USBDEVFS_CAP_ZERO_PACKET | USBDEVFS_CAP_NO_PACKET_SIZE_LIM | USBDEVFS_CAP_REAP_AFTER_DISCONNECT | USBDEVFS_CAP_MMAP | - USBDEVFS_CAP_DROP_PRIVILEGES | USBDEVFS_CAP_CONNINFO_EX; + USBDEVFS_CAP_DROP_PRIVILEGES | + USBDEVFS_CAP_CONNINFO_EX | MAYBE_CAP_SUSPEND; if (!ps->dev->bus->no_stop_on_short) caps |= USBDEVFS_CAP_BULK_CONTINUATION; if (ps->dev->bus->sg_tablesize) @@ -2376,6 +2415,47 @@ static int proc_drop_privileges(struct usb_dev_state *ps, void __user *arg) return 0; } +static int proc_forbid_suspend(struct usb_dev_state *ps) +{ + int ret = 0; + + if (ps->suspend_allowed) { + ret = usb_autoresume_device(ps->dev); + if (ret == 0) + ps->suspend_allowed = false; + else if (ret != -ENODEV) + ret = -EIO; + } + return ret; +} + +static int proc_allow_suspend(struct usb_dev_state *ps) +{ + if (!connected(ps)) + return -ENODEV; + + WRITE_ONCE(ps->not_yet_resumed, 1); + if (!ps->suspend_allowed) { + usb_autosuspend_device(ps->dev); + ps->suspend_allowed = true; + } + return 0; +} + +static int proc_wait_for_resume(struct usb_dev_state *ps) +{ + int ret; + + usb_unlock_device(ps->dev); + ret = wait_event_interruptible(ps->wait_for_resume, + READ_ONCE(ps->not_yet_resumed) == 0); + usb_lock_device(ps->dev); + + if (ret != 0) + return -EINTR; + return proc_forbid_suspend(ps); +} + /* * NOTE: All requests here that have interface numbers as parameters * are assuming that somehow the configuration has been prevented from @@ -2570,6 +2650,15 @@ static long usbdev_do_ioctl(struct file *file, unsigned int cmd, case USBDEVFS_GET_SPEED: ret = ps->dev->speed; break; + case USBDEVFS_FORBID_SUSPEND: + ret = proc_forbid_suspend(ps); + break; + case USBDEVFS_ALLOW_SUSPEND: + ret = proc_allow_suspend(ps); + break; + case USBDEVFS_WAIT_FOR_RESUME: + ret = proc_wait_for_resume(ps); + break; } /* Handle variable-length commands */ @@ -2643,15 +2732,20 @@ static void usbdev_remove(struct usb_device *udev) { struct usb_dev_state *ps; + /* Protect against simultaneous resume */ + mutex_lock(&usbfs_mutex); while (!list_empty(&udev->filelist)) { ps = list_entry(udev->filelist.next, struct usb_dev_state, list); destroy_all_async(ps); wake_up_all(&ps->wait); + WRITE_ONCE(ps->not_yet_resumed, 0); + wake_up_all(&ps->wait_for_resume); list_del_init(&ps->list); if (ps->discsignr) kill_pid_usb_asyncio(ps->discsignr, EPIPE, ps->disccontext, ps->disc_pid, ps->cred); } + mutex_unlock(&usbfs_mutex); } static int usbdev_notify(struct notifier_block *self, |