From: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Date: Fri, 23 Nov 2012 19:55:06 +0000 (+0100)
Subject: PM / QoS: fix wrong error-checking condition
X-Git-Tag: v3.6.9~23
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=dc541b2ba0e0aa83831ca99ba1e5a574e41d3c5b;p=thirdparty%2Fkernel%2Fstable.git

PM / QoS: fix wrong error-checking condition

commit a7227a0faa117d0bc532aea546ae5ac5f89e8ed7 upstream.

dev_pm_qos_add_request() can return 0, 1, or a negative error code,
therefore the correct error test is "if (error < 0)." Checking just for
non-zero return code leads to erroneous setting of the req->dev pointer
to NULL, which then leads to a repeated call to
dev_pm_qos_add_ancestor_request() in st1232_ts_irq_handler(). This in turn
leads to an Oops, when the I2C host adapter is unloaded and reloaded again
because of the inconsistent state of its QoS request list.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c
index 74a67e0019a2d..fbbd4ed2edf28 100644
--- a/drivers/base/power/qos.c
+++ b/drivers/base/power/qos.c
@@ -451,7 +451,7 @@ int dev_pm_qos_add_ancestor_request(struct device *dev,
 	if (ancestor)
 		error = dev_pm_qos_add_request(ancestor, req, value);
 
-	if (error)
+	if (error < 0)
 		req->dev = NULL;
 
 	return error;