From f790923f146140a261ad211e5baf75d169f16fb2 Mon Sep 17 00:00:00 2001
From: Stefan Popa <stefan.popa@analog.com>
Date: Thu, 14 Sep 2017 16:50:28 +0300
Subject: [PATCH] staging: iio: ad7192: Fix - use the dedicated reset function avoiding dma from stack.
Git-commit: f790923f146140a261ad211e5baf75d169f16fb2
Patch-mainline: v4.14-rc4
References: bsc#1051510

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>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/staging/iio/adc/ad7192.c |    4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

--- a/drivers/staging/iio/adc/ad7192.c
+++ b/drivers/staging/iio/adc/ad7192.c
@@ -223,11 +223,9 @@ static int ad7192_setup(struct ad7192_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 */