Patch "staging: iio: ad7192: Fix - use the dedicated reset function avoiding dma from stack." has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

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

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     staging-iio-ad7192-fix-use-the-dedicated-reset-function-avoiding-dma-from-stack.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


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

From: Stefan Popa <stefan.popa@analog.com>

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>

---
 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
@@ -222,11 +222,9 @@ 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 */


Patches currently in stable-queue which might be from stefan.popa@analog.com are

queue-4.9/staging-iio-ad7192-fix-use-the-dedicated-reset-function-avoiding-dma-from-stack.patch