[PATCH v2] mfd: mc13xxx-core: Initialize the lock prior to using it

From: Fabio Estevam
Date: Tue Apr 15 2014 - 18:56:40 EST


From: Fabio Estevam <fabio.estevam@xxxxxxxxxxxxx>

After request_threaded_irq() is called there is a chance that an interrupt
may occur before the 'mc13xxx->lock' is initialized, which will trigger a kernel
oops.

In order to prevent that, move the initialization of 'mc13xxx->lock' prior to
requesting the interrupts.

Suggested-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>
Signed-off-by: Fabio Estevam <fabio.estevam@xxxxxxxxxxxxx>
---
Changes since v1:
- Changed kernel warning --> kernel oops to better describe the problem
- Added Russell's Ack

drivers/mfd/mc13xxx-core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mfd/mc13xxx-core.c b/drivers/mfd/mc13xxx-core.c
index 06e64b6..9e296c4 100644
--- a/drivers/mfd/mc13xxx-core.c
+++ b/drivers/mfd/mc13xxx-core.c
@@ -660,13 +660,13 @@ int mc13xxx_common_init(struct device *dev)
if (ret)
return ret;

+ mutex_init(&mc13xxx->lock);
+
ret = request_threaded_irq(mc13xxx->irq, NULL, mc13xxx_irq_thread,
IRQF_ONESHOT | IRQF_TRIGGER_HIGH, "mc13xxx", mc13xxx);
if (ret)
return ret;

- mutex_init(&mc13xxx->lock);
-
if (mc13xxx_probe_flags_dt(mc13xxx) < 0 && pdata)
mc13xxx->flags = pdata->flags;

--
1.8.3.2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/