[PATCH 140/241] PM / QoS: fix wrong error-checking condition
Herton Ronaldo Krzesinski
herton.krzesinski at canonical.com
Thu Dec 13 13:58:25 UTC 2012
3.5.7.2 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Guennadi Liakhovetski <g.liakhovetski at gmx.de>
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 at gmx.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
---
drivers/base/power/qos.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c
index fd849a2..b95ebf2 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;
--
1.7.9.5
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