PM / QoS: fix wrong error-checking condition
Guennadi Liakhovetski [Fri, 23 Nov 2012 19:55:06 +0000 (20:55 +0100)]
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>

drivers/base/power/qos.c

index 7185557..c365c93 100644 (file)
@@ -446,7 +446,7 @@ 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;