From patchwork Thu Dec 13 13:58:25 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [140/241] PM / QoS: fix wrong error-checking condition From: Herton Ronaldo Krzesinski X-Patchwork-Id: 205990 Message-Id: <1355407206-17100-141-git-send-email-herton.krzesinski@canonical.com> To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: "Rafael J. Wysocki" , Guennadi Liakhovetski Date: Thu, 13 Dec 2012 11:58:25 -0200 3.5.7.2 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Guennadi Liakhovetski 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 Signed-off-by: Rafael J. Wysocki Signed-off-by: Herton Ronaldo Krzesinski --- 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;