Update Linux to v5.4.148
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz
Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
index 73aee59..94fde39 100644
--- a/drivers/iio/adc/stm32-adc.c
+++ b/drivers/iio/adc/stm32-adc.c
@@ -1367,8 +1367,30 @@
static void stm32_adc_dma_buffer_done(void *data)
{
struct iio_dev *indio_dev = data;
+ struct stm32_adc *adc = iio_priv(indio_dev);
+ int residue = stm32_adc_dma_residue(adc);
- iio_trigger_poll_chained(indio_dev->trig);
+ /*
+ * In DMA mode the trigger services of IIO are not used
+ * (e.g. no call to iio_trigger_poll).
+ * Calling irq handler associated to the hardware trigger is not
+ * relevant as the conversions have already been done. Data
+ * transfers are performed directly in DMA callback instead.
+ * This implementation avoids to call trigger irq handler that
+ * may sleep, in an atomic context (DMA irq handler context).
+ */
+ dev_dbg(&indio_dev->dev, "%s bufi=%d\n", __func__, adc->bufi);
+
+ while (residue >= indio_dev->scan_bytes) {
+ u16 *buffer = (u16 *)&adc->rx_buf[adc->bufi];
+
+ iio_push_to_buffers(indio_dev, buffer);
+
+ residue -= indio_dev->scan_bytes;
+ adc->bufi += indio_dev->scan_bytes;
+ if (adc->bufi >= adc->rx_buf_sz)
+ adc->bufi = 0;
+ }
}
static int stm32_adc_dma_start(struct iio_dev *indio_dev)
@@ -1735,15 +1757,27 @@
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_slave_channel(&indio_dev->dev, "rx");
- if (!adc->dma_chan)
+ 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(dev,
+ "DMA channel request failed with %d\n",
+ ret);
+ return ret;
+ }
+
+ /* DMA is optional: fall back to IRQ mode */
+ adc->dma_chan = NULL;
return 0;
+ }
adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev,
STM32_DMA_BUFFER_SIZE,
@@ -1778,6 +1812,7 @@
{
struct iio_dev *indio_dev;
struct device *dev = &pdev->dev;
+ irqreturn_t (*handler)(int irq, void *p) = NULL;
struct stm32_adc *adc;
int ret;
@@ -1839,13 +1874,15 @@
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;
+ if (!adc->dma_chan)
+ handler = &stm32_adc_trigger_handler;
+
ret = iio_triggered_buffer_setup(indio_dev,
- &iio_pollfunc_store_time,
- &stm32_adc_trigger_handler,
+ &iio_pollfunc_store_time, handler,
&stm32_adc_buffer_setup_ops);
if (ret) {
dev_err(&pdev->dev, "buffer setup failed\n");