Merge "usb: gadget: Fix race condition between function wakeup and bus resume" (1d63465e) · Commits · e / devices / android_kernel_sony_msm8994

drivers/usb/gadget/composite.c

+55 −24

Original line number	Diff line number	Diff line
		@@ -363,11 +363,13 @@ int usb_get_func_interface_id(struct usb_function *func)
		return -ENODEV;
		}

		int usb_func_wakeup(struct usb_function *func)
		static int _usb_func_wakeup(struct usb_function *func, bool use_pending_flag)
		{
		int ret;
		unsigned interface_id;
		int interface_id;
		unsigned long flags;
		struct usb_gadget *gadget;
		struct usb_composite_dev *cdev;

		pr_debug("%s function wakeup\n",
		func->name ? func->name : "");
		@@ -386,6 +388,15 @@ int usb_func_wakeup(struct usb_function *func)
		return -ENOTSUPP;
		}

		cdev = get_gadget_data(gadget);
		spin_lock_irqsave(&cdev->lock, flags);

		if (use_pending_flag && !func->func_wakeup_pending) {
		pr_debug("Pending flag is cleared - Function wakeup is cancelled.\n");
		spin_unlock_irqrestore(&cdev->lock, flags);
		return 0;
		}

		ret = usb_get_func_interface_id(func);
		if (ret < 0) {
		ERROR(func->config->cdev,
		@@ -396,27 +407,38 @@ int usb_func_wakeup(struct usb_function *func)

		interface_id = ret;
		ret = usb_gadget_func_wakeup(gadget, interface_id);
		if (ret) {

		if (use_pending_flag)
		func->func_wakeup_pending = false;

		spin_unlock_irqrestore(&cdev->lock, flags);

		return ret;
		}

		int usb_func_wakeup(struct usb_function *func)
		{
		int ret;

		pr_debug("%s function wakeup\n",
		func->name ? func->name : "");

		ret = _usb_func_wakeup(func, false);
		if (ret == -EAGAIN) {
		DBG(func->config->cdev,
		"Function wakeup for %s could not complete due to suspend state. Delayed until after bus resume.\n",
		func->name ? func->name : "");
		func->func_wakeup_pending = true;
		ret = 0;
		} else {
		} else if (ret < 0) {
		ERROR(func->config->cdev,
		"Failed to wake function %s from suspend state. interface id: %d, ret=%d. Canceling USB request.\n",
		func->name ? func->name : "",
		interface_id, ret);
		"Failed to wake function %s from suspend state. ret=%d. Canceling USB request.\n",
		func->name ? func->name : "", ret);
		}

		return ret;
		}

		func->func_wakeup_pending = false;
		return 0;
		}

		static u8 encode_bMaxPower(enum usb_device_speed speed,
		struct usb_configuration *c)
		{
		@@ -677,6 +699,7 @@ static void reset_config(struct usb_composite_dev *cdev)
		/* USB 3.0 addition */
		f->func_is_suspended = false;
		f->func_wakeup_allowed = false;
		f->func_wakeup_pending = false;

		bitmap_zero(f->endpoints, 32);
		}
		@@ -1882,14 +1905,22 @@ composite_resume(struct usb_gadget *gadget)
		DBG(cdev, "resume\n");
		if (cdev->driver->resume)
		cdev->driver->resume(cdev);

		if (cdev->config) {
		list_for_each_entry(f, &cdev->config->functions, list) {
		if (f->func_wakeup_pending) {
		ret = usb_func_wakeup(f);
		if (ret)
		ERROR(cdev,
		"Failed to send function wakeup notification for the %s function. Error code: %d\n",
		f->name ? f->name : "", ret);
		ret = _usb_func_wakeup(f, true);
		if (ret) {
		if (ret == -EAGAIN) {
		ERROR(f->config->cdev,
		"Function wakeup for %s could not complete due to suspend state.\n",
		f->name ? f->name : "");
		break;
		} else {
		ERROR(f->config->cdev,
		"Failed to wake function %s from suspend state. ret=%d. Canceling USB request.\n",
		f->name ? f->name : "",
		ret);
		}
		}

		if (f->resume)

drivers/usb/gadget/u_bam_data.c

+15 −7

Original line number	Diff line number	Diff line
		@@ -1525,15 +1525,23 @@ static int bam_data_wake_cb(void *param)
		if ((gadget->speed == USB_SPEED_SUPER) && (func->func_is_suspended)) {
		if (!func->func_wakeup_allowed)
		return -ENOTSUPP;
		else
		usb_func_wakeup(func);
		else {
		ret = usb_func_wakeup(func);
		if (ret)
		pr_err("Function wakeup failed. ret=%d\n", ret);
		}

		} else {
		ret = usb_gadget_wakeup(gadget);
		if (ret) {
		pr_err("Failed to wake up the USB core. ret=%d", ret);
		if ((ret == -EBUSY) \|\| (ret == -EAGAIN))
		pr_debug("Remote wakeup is delayed due to low-power mode exit.\n");
		else
		pr_err("Failed to wake up the USB core. ret=%d.\n",
		ret);

		return ret;
		}
		}

		return 0;
		}