staging: iio: ad7192: Fix - use the dedicated reset function avoiding dma from stack.

BugLink: http://bugs.launchpad.net/bugs/1723145
commit f790923f146140a261ad211e5baf75d169f16fb2 upstream.

Depends on: 691c4b95d1 ("iio: ad_sigma_delta: Implement a dedicated reset function")

SPI host drivers can use DMA to transfer data, so the buffer should be properly allocated.
Keeping it on the stack could cause an undefined behavior.

The dedicated reset function solves this issue.

Signed-off-by: Stefan Popa <stefan.popa@analog.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>

diff --git a/drivers/staging/iio/adc/ad7192.c b/drivers/staging/iio/adc/ad7192.c
index d11c6de9c777f979a2a59b05cd82fc8ed0c54e0b..6150d2780e22c57479c95d59afaea1cbc2b385a5 100644 (file)
--- a/drivers/staging/iio/adc/ad7192.c
+++ b/drivers/staging/iio/adc/ad7192.c
@@ -223,11 +223,9 @@ static int ad7192_setup(struct ad7192_state *st,
        struct iio_dev *indio_dev = spi_get_drvdata(st->sd.spi);
        unsigned long long scale_uv;
        int i, ret, id;
-       u8 ones[6];
 
        /* reset the serial interface */
-       memset(&ones, 0xFF, 6);
-       ret = spi_write(st->sd.spi, &ones, 6);
+       ret = ad_sd_reset(&st->sd, 48);
        if (ret < 0)
                goto out;
        usleep_range(500, 1000); /* Wait for at least 500us */