Re: [PATCH v2] iio: adc: ti_am335x_adc: Fix return value check of tiadc_request_dma()

[Jonathan Cameron <jic23@kernel.org>]

On Mon, 27 Nov 2023 15:14:29 +0530
Bhavya Kapoor <b-kapoor@ti.com> wrote:

> LGTM !!🙂
> 
> On 24/11/23 5:41 pm, Wadim Egorov wrote:
> >
> > Am 05.10.23 um 16:09 schrieb Jonathan Cameron:  
> >> On Mon, 25 Sep 2023 15:44:27 +0200
> >> Wadim Egorov <w.egorov@phytec.de> wrote:
> >>  
> >>> 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>

Applied to the fixes-togreg branch of iio.git and marked for stable.

> >> +CC Bhavya,
> >>
> >> Could you take a look at this given you had comments on v1.  
> >
> > Bhavya, any comments on this?
> > If not, is there anything else that is blocking this patch?
> >
> > Regards,
> > Wadim
> >  
> >>
> >> Thanks,
> >>
> >> Jonathan
> >>  
> >>> ---
> >>> v2:
> >>>    - Update description
> >>>    - Drop line break after Fixes tag
> >>>    - Move decision about optional DMA into probe/caller
> >>> ---
> >>>   drivers/iio/adc/ti_am335x_adc.c | 4 +++-
> >>>   1 file changed, 3 insertions(+), 1 deletion(-)
> >>>
> >>> diff --git a/drivers/iio/adc/ti_am335x_adc.c 
> >>> b/drivers/iio/adc/ti_am335x_adc.c
> >>> index 8db7a01cb5fb..5f8795986995 100644
> >>> --- 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;