Commit 90af01f6 authored Apr 30, 2020 by Fabrice Gasnier Committed by Greg Kroah-Hartman May 27, 2020

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



[ Upstream commit 52cd91c27f3908b88e8b25aed4a4d20660abcc45 ]

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: 2763ea05 ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent cdaedaba

drivers/iio/adc/stm32-adc.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -1682,18 +1682,18 @@ 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;
		@@ -1816,7 +1816,7 @@ static int stm32_adc_probe(struct platform_device *pdev)
		if (ret < 0)
		goto err_clk_disable;

		ret = stm32_adc_dma_request(indio_dev);
		ret = stm32_adc_dma_request(dev, indio_dev);
		if (ret < 0)
		goto err_clk_disable;