patch "iio: adc: stm32-adc: fix device used to request dma" added to staging-linus

[<gregkh@linuxfoundation.org>]

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

    iio: adc: stm32-adc: fix device used to request dma

to my staging git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git
in the staging-linus branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.

If you have any questions about this process, please let me know.


From 52cd91c27f3908b88e8b25aed4a4d20660abcc45 Mon Sep 17 00:00:00 2001
From: Fabrice Gasnier <fabrice.gasnier@st.com>
Date: Thu, 30 Apr 2020 11:28:45 +0200
Subject: iio: adc: stm32-adc: fix device used to request dma

DMA channel request should use device struct from platform device struct.
Currently it's using iio device struct. But at this stage when probing,
device struct isn't yet registered (e.g. device_register is done in
iio_device_register). Since commit 71723a96b8b1 ("dmaengine: Create
symlinks between DMA channels and slaves"), a warning message is printed
as the links in sysfs can't be created, due to device isn't yet registered:
- Cannot create DMA slave symlink
- Cannot create DMA dma:rx symlink

Fix this by using device struct from platform device to request dma chan.

Fixes: 2763ea0585c99 ("iio: adc: stm32: add optional dma support")

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 drivers/iio/adc/stm32-adc.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
index ae622ee6d08c..dfc3a306c667 100644
--- a/drivers/iio/adc/stm32-adc.c
+++ b/drivers/iio/adc/stm32-adc.c
@@ -1812,18 +1812,18 @@ static int stm32_adc_chan_of_init(struct iio_dev *indio_dev)
 	return 0;
 }
 
-static int stm32_adc_dma_request(struct iio_dev *indio_dev)
+static int stm32_adc_dma_request(struct device *dev, struct iio_dev *indio_dev)
 {
 	struct stm32_adc *adc = iio_priv(indio_dev);
 	struct dma_slave_config config;
 	int ret;
 
-	adc->dma_chan = dma_request_chan(&indio_dev->dev, "rx");
+	adc->dma_chan = dma_request_chan(dev, "rx");
 	if (IS_ERR(adc->dma_chan)) {
 		ret = PTR_ERR(adc->dma_chan);
 		if (ret != -ENODEV) {
 			if (ret != -EPROBE_DEFER)
-				dev_err(&indio_dev->dev,
+				dev_err(dev,
 					"DMA channel request failed with %d\n",
 					ret);
 			return ret;
@@ -1930,7 +1930,7 @@ static int stm32_adc_probe(struct platform_device *pdev)
 	if (ret < 0)
 		return ret;
 
-	ret = stm32_adc_dma_request(indio_dev);
+	ret = stm32_adc_dma_request(dev, indio_dev);
 	if (ret < 0)
 		return ret;
 
-- 
2.26.2