On Thu, 18 Nov 2021 13:51:44 +0100
Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx> wrote:
> Hello Olivier,
>
> On 18.11.21 13:39, Olivier Moysan wrote:
> > dev_err_probe() calls __device_set_deferred_probe_reason()
> > on -EPROBE_DEFER error.
> > If device pointer to driver core private structure is not initialized,
> > a null pointer error occurs.
> > This pointer is set too late on iio_device_register() call, for iio device.
>
> Even if it were set earlier, you should call dev_err_probe with the dev of
> the probe that's currently running. Not any other devices you created since
> then.
+1 on that
>
> > So use parent device instead for dev_err_probe() call.
> >
> > Fixes: 0e346b2cfa85 ("iio: adc: stm32-adc: add vrefint calibration support")
> >
No line break between these two tags. Greg will reject a pull if there
is one (and 0-day probably complain about it...)
Jonathan
> > Signed-off-by: Olivier Moysan <olivier.moysan@xxxxxxxxxxx>
> > ---
> > drivers/iio/adc/stm32-adc.c | 6 ++++--
> > 1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
> > index 7f1fb36c747c..14c7c9d390e8 100644
> > --- a/drivers/iio/adc/stm32-adc.c
> > +++ b/drivers/iio/adc/stm32-adc.c
> > @@ -217,6 +217,7 @@ struct stm32_adc_cfg {
> >
> > /**
> > * struct stm32_adc - private data of each ADC IIO instance
> > + * dev: parent device
> > * @common: reference to ADC block common data
> > * @offset: ADC instance register offset in ADC block
> > * @cfg: compatible configuration data
> > @@ -243,6 +244,7 @@ struct stm32_adc_cfg {
> > * @int_ch: internal channel indexes array
> > */
> > struct stm32_adc {
> > + struct device *dev;
>
> Can't you use the parent pointer of the indio_dev?
>
> > struct stm32_adc_common *common;
> > u32 offset;
> > const struct stm32_adc_cfg *cfg;
> > @@ -1986,8 +1988,7 @@ static int stm32_adc_populate_int_ch(struct iio_dev *indio_dev, const char *ch_n
> > /* Get calibration data for vrefint channel */
> > ret = nvmem_cell_read_u16(&indio_dev->dev, "vrefint", &vrefint);
> > if (ret && ret != -ENOENT) {
> > - return dev_err_probe(&indio_dev->dev, ret,
> > - "nvmem access error\n");
> > + return dev_err_probe(adc->dev, ret, "nvmem access error\n");
> > }
> > if (ret == -ENOENT)
> > dev_dbg(&indio_dev->dev, "vrefint calibration not found\n");
> > @@ -2221,6 +2222,7 @@ static int stm32_adc_probe(struct platform_device *pdev)
> > init_completion(&adc->completion);
> > adc->cfg = (const struct stm32_adc_cfg *)
> > of_match_device(dev->driver->of_match_table, dev)->data;
> > + adc->dev = &pdev->dev;
>
> There's struct device *dev = &pdev->dev; defined earlier, so you can use dev instead.
>
> >
> > indio_dev->name = dev_name(&pdev->dev);
> > indio_dev->dev.of_node = pdev->dev.of_node;
> >
>
> Cheers,
> Ahmad
>
