From: Benoit Goby <benoit@android.com>
Date: Mon, 22 Nov 2010 22:46:05 +0000 (-0800)
Subject: usb: core: Temporary workaround for usb auto-suspend issue
X-Git-Tag: firefly_0821_release~9834^2~319
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=463100c1cedd5684188c8d5ece84c4af6dd42090;p=firefly-linux-kernel-4.4.55.git

usb: core: Temporary workaround for usb auto-suspend issue

If a device aborts suspend, usb_resume may be called on a device whose
parent has been auto-suspended. Recursively resume its parents and
change their runtime pm state.

Change-Id: I8f96482bdafae3888a0df9cb30422236a001e17d
Signed-off-by: Benoit Goby <benoit@android.com>
---

diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index d7a4401ef019..ffa3e22083c2 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -1324,6 +1324,20 @@ int usb_resume(struct device *dev, pm_message_t msg)
 	 * Unbind the interfaces that will need rebinding later.
 	 */
 	} else {
+		/* If a device aborts suspend, usb_resume may be called on a
+		 * device whose parent has been auto-suspended. Recursively
+		 * resume its parents and change their runtime pm state.
+		 */
+		if (udev->parent && msg.event == PM_EVENT_RESUME
+			    && udev->parent->state == USB_STATE_SUSPENDED) {
+			status = usb_resume(&udev->parent->dev, msg);
+			if (status) {
+				dev_err(dev, "%s: failed to resume parent\n",
+						__func__);
+				return status;
+			}
+		}
+
 		status = usb_resume_both(udev, msg);
 		if (status == 0) {
 			pm_runtime_disable(dev);