5.1-stable patches

[thirdparty/kernel/stable-queue.git] / releases / 3.1.1 / usb-for-usb_autopm_get_interface_async-einprogress-is-not-an-error.patch

From c5a48592d874ddef8c7880311581eccf0eb30c3b Mon Sep 17 00:00:00 2001
From: Jim Wylder <jwylder1@motorola.com>
Date: Tue, 6 Sep 2011 21:07:20 -0500
Subject: USB: for usb_autopm_get_interface_async -EINPROGRESS is not an error

From: Jim Wylder <jwylder1@motorola.com>

commit c5a48592d874ddef8c7880311581eccf0eb30c3b upstream.

A return value of -EINPROGRESS from pm_runtime_get indicates that
the device is already resuming due to a previous call.  Internally,
usb_autopm_get_interface_async doesn't treat this as an error and
increments the usage count, but passes the error status along
to the caller.  The logical assumption of the caller is that
any negative return value reflects the device not resuming
and the pm_usage_cnt not being incremented.  Since the usage count
is being incremented and the device is resuming, return success (0)
instead.

Signed-off-by: James Wylder <james.wylder@motorola.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 drivers/usb/core/driver.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -1583,7 +1583,7 @@ int usb_autopm_get_interface_async(struc
 	dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
 			__func__, atomic_read(&intf->dev.power.usage_count),
 			status);
-	if (status > 0)
+	if (status > 0 || status == -EINPROGRESS)
 		status = 0;
 	return status;
 }