Input: ads7846 - return error on regulator_get() failure

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@deeprootsystems.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 532279cda0e4989de8aa45e3791f920d5c82c92b..634f6f6b9b1349a27bcca9a056ca27a1b5151abc 100644 (file)
--- 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;
        }