[PATCH] input: touchscreen: ads7846: return error on probe failure

[Kevin Hilman]

In probe(), if regulator_get() failed, an error code was not being
returned causing the driver to be successfully bound, even though
probe failed.  This in turn caused the suspend, resume and remove
methods to be registered and accessed via the SPI core.  Since these
functions all access private driver data using pointers that had been
freed during the failed probe, this would lead to unpredictable
behavior.

This patch ensures that probe() returns an error code in this failure
case so the driver is not bound.

Found using lockdep and noticing the lock used in the suspend/resum
path pointed to a bogus lock due to the freed memory.

Signed-off-by: Kevin Hilman <khilman@xxxxxxxxxxxxxxxxxxx>
---
 drivers/input/touchscreen/ads7846.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 532279c..634f6f6 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -1163,8 +1163,8 @@ static int __devinit ads7846_probe(struct spi_device *spi)
 
 	ts->reg = regulator_get(&spi->dev, "vcc");
 	if (IS_ERR(ts->reg)) {
-		dev_err(&spi->dev, "unable to get regulator: %ld\n",
-			PTR_ERR(ts->reg));
+		err = PTR_ERR(ts->reg);
+		dev_err(&spi->dev, "unable to get regulator: %ld\n", err);
 		goto err_free_gpio;
 	}
 
-- 
1.7.0.2

--
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/