PM / QoS: fix wrong error-checking condition

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>
Cc: <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c
index 74a67e0019a2d246820ccb2858399bca193ff789..fbbd4ed2edf288318f8d165760c91ee420f1812c 100644 (file)
--- 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;