iio: adc: ti_am335x_adc: Fix return value check of tiadc_request_dma()

commit 60576e84c187043cef11f11d015249e71151d35a upstream.

Fix wrong handling of a DMA request where the probing only failed
if -EPROPE_DEFER was returned. Instead, let us fail if a non -ENODEV
value is returned. This makes DMAs explicitly optional. Even if the
DMA request is unsuccessfully, the ADC can still work properly.
We do also handle the defer probe case by making use of dev_err_probe().

Fixes: f438b9da75eb ("drivers: iio: ti_am335x_adc: add dma support")
Signed-off-by: Wadim Egorov <w.egorov@phytec.de>
Reviewed-by: Bhavya Kapoor <b-kapoor@ti.com>
Link: https://lore.kernel.org/r/20230925134427.214556-1-w.egorov@phytec.de
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c
index 8db7a01cb5fbf3f78f7f8e26a587c2b698ba2cae..5f879598699545f1ccff9ad8f62e50d29353f659 100644 (file)
--- a/drivers/iio/adc/ti_am335x_adc.c
+++ b/drivers/iio/adc/ti_am335x_adc.c
@@ -670,8 +670,10 @@ static int tiadc_probe(struct platform_device *pdev)
        platform_set_drvdata(pdev, indio_dev);
 
        err = tiadc_request_dma(pdev, adc_dev);
-       if (err && err == -EPROBE_DEFER)
+       if (err && err != -ENODEV) {
+               dev_err_probe(&pdev->dev, err, "DMA request failed\n");
                goto err_dma;
+       }
 
        return 0;