Merge branch 'bkl' into for-linus (9f17d516) · Commits · e / devices / android_kernel_xiaomi_markw

drivers/hid/usbhid/hiddev.c

+12 −42

Original line number	Diff line number	Diff line
		@@ -67,7 +67,7 @@ struct hiddev_list {
		struct mutex thread_lock;
		};

		static struct hiddev *hiddev_table[HIDDEV_MINORS];
		static struct usb_driver hiddev_driver;

		/*
		* Find a report, given the report's type and ID. The ID can be specified
		@@ -265,22 +265,19 @@ static int hiddev_release(struct inode * inode, struct file * file)
		static int hiddev_open(struct inode inode, struct file file)
		{
		struct hiddev_list *list;
		int res, i;

		/* See comment in hiddev_connect() for BKL explanation */
		lock_kernel();
		i = iminor(inode) - HIDDEV_MINOR_BASE;
		struct usb_interface *intf;
		struct hiddev *hiddev;
		int res;

		if (i >= HIDDEV_MINORS \|\| i < 0 \|\| !hiddev_table[i])
		intf = usb_find_interface(&hiddev_driver, iminor(inode));
		if (!intf)
		return -ENODEV;
		hiddev = usb_get_intfdata(intf);

		if (!(list = kzalloc(sizeof(struct hiddev_list), GFP_KERNEL)))
		return -ENOMEM;
		mutex_init(&list->thread_lock);

		list->hiddev = hiddev_table[i];


		list->hiddev = hiddev;
		file->private_data = list;

		/*
		@@ -289,7 +286,7 @@ static int hiddev_open(struct inode inode, struct file file)
		*/
		if (list->hiddev->exist) {
		if (!list->hiddev->open++) {
		res = usbhid_open(hiddev_table[i]->hid);
		res = usbhid_open(hiddev->hid);
		if (res < 0) {
		res = -EIO;
		goto bail;
		@@ -301,12 +298,12 @@ static int hiddev_open(struct inode inode, struct file file)
		}

		spin_lock_irq(&list->hiddev->list_lock);
		list_add_tail(&list->node, &hiddev_table[i]->list);
		list_add_tail(&list->node, &hiddev->list);
		spin_unlock_irq(&list->hiddev->list_lock);

		if (!list->hiddev->open++)
		if (list->hiddev->exist) {
		struct hid_device *hid = hiddev_table[i]->hid;
		struct hid_device *hid = hiddev->hid;
		res = usbhid_get_power(hid);
		if (res < 0) {
		res = -EIO;
		@@ -314,13 +311,10 @@ static int hiddev_open(struct inode inode, struct file file)
		}
		usbhid_open(hid);
		}

		unlock_kernel();
		return 0;
		bail:
		file->private_data = NULL;
		kfree(list);
		unlock_kernel();
		return res;
		}

		@@ -894,37 +888,14 @@ int hiddev_connect(struct hid_device *hid, unsigned int force)
		hid->hiddev = hiddev;
		hiddev->hid = hid;
		hiddev->exist = 1;

		/*
		* BKL here is used to avoid race after usb_register_dev().
		* Once the device node has been created, open() could happen on it.
		* The code below will then fail, as hiddev_table hasn't been
		* updated.
		*
		* The obvious fix -- introducing mutex to guard hiddev_table[]
		* doesn't work, as usb_open() and usb_register_dev() both take
		* minor_rwsem, thus we'll have ABBA deadlock.
		*
		* Before BKL pushdown, usb_open() had been acquiring it in right
		* order, so _open() was safe to use it to protect from this race.
		* Now the order is different, but AB-BA deadlock still doesn't occur
		* as BKL is dropped on schedule() (i.e. while sleeping on
		* minor_rwsem). Fugly.
		*/
		lock_kernel();
		usb_set_intfdata(usbhid->intf, usbhid);
		retval = usb_register_dev(usbhid->intf, &hiddev_class);
		if (retval) {
		err_hid("Not able to get a minor for this device.");
		hid->hiddev = NULL;
		unlock_kernel();
		kfree(hiddev);
		return -1;
		} else {
		hid->minor = usbhid->intf->minor;
		hiddev_table[usbhid->intf->minor - HIDDEV_MINOR_BASE] = hiddev;
		}
		unlock_kernel();

		return 0;
		}

		@@ -942,7 +913,6 @@ void hiddev_disconnect(struct hid_device *hid)
		hiddev->exist = 0;
		mutex_unlock(&hiddev->existancelock);

		hiddev_table[hiddev->hid->minor - HIDDEV_MINOR_BASE] = NULL;
		usb_deregister_dev(usbhid->intf, &hiddev_class);

		if (hiddev->open) {