From ab147668873c40d16de4920832bc1f2ccf0da3c5 Mon Sep 17 00:00:00 2001
From: Ming Lei <ming.lei@canonical.com>
Date: Fri, 22 Feb 2013 16:34:22 -0800
Subject: [PATCH] --- yaml --- r: 356557 b: refs/heads/master c:
 4d769def244806562de1baa3acb39726131fbe6a h: refs/heads/master i:   356555:
 f645f6cd5c489d4a0d896933cc4b41e7897bdaa9 v: v3

---
 [refs]                       |  2 +-
 trunk/drivers/usb/core/hub.c | 13 +++++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 3c461258de75..b0ebe6577ca7 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: db88175f41a29c1ffff1a6938a7969d206a47326
+refs/heads/master: 4d769def244806562de1baa3acb39726131fbe6a
diff --git a/trunk/drivers/usb/core/hub.c b/trunk/drivers/usb/core/hub.c
index 1775ad471edd..5480352f984d 100644
--- a/trunk/drivers/usb/core/hub.c
+++ b/trunk/drivers/usb/core/hub.c
@@ -5177,6 +5177,7 @@ int usb_reset_device(struct usb_device *udev)
 {
 	int ret;
 	int i;
+	unsigned int noio_flag;
 	struct usb_host_config *config = udev->actconfig;
 
 	if (udev->state == USB_STATE_NOTATTACHED ||
@@ -5186,6 +5187,17 @@ int usb_reset_device(struct usb_device *udev)
 		return -EINVAL;
 	}
 
+	/*
+	 * Don't allocate memory with GFP_KERNEL in current
+	 * context to avoid possible deadlock if usb mass
+	 * storage interface or usbnet interface(iSCSI case)
+	 * is included in current configuration. The easist
+	 * approach is to do it for every device reset,
+	 * because the device 'memalloc_noio' flag may have
+	 * not been set before reseting the usb device.
+	 */
+	noio_flag = memalloc_noio_save();
+
 	/* Prevent autosuspend during the reset */
 	usb_autoresume_device(udev);
 
@@ -5230,6 +5242,7 @@ int usb_reset_device(struct usb_device *udev)
 	}
 
 	usb_autosuspend_device(udev);
+	memalloc_noio_restore(noio_flag);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(usb_reset_device);