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Message-ID: <6eb4608b-10e1-7fcc-b73f-4445150216e0@ti.com>
Date:   Mon, 18 Sep 2023 14:18:07 +0530
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Subject: Re: [PATCH] iio: adc: ti_am335x_adc: Make DMAs optional
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To:     Wadim Egorov <w.egorov@phytec.de>, <jic23@kernel.org>,
        <lars@metafoo.de>, <robh@kernel.org>, <heiko@sntech.de>,
        <mugunthanvnm@ti.com>, <peter.ujfalusi@ti.com>
CC:     <linux-iio@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <upstream@lists.phytec.de>, <nm@ti.com>
References: <20230914121300.845493-1-w.egorov@phytec.de>
From:   Bhavya Kapoor <b-kapoor@ti.com>
In-Reply-To: <20230914121300.845493-1-w.egorov@phytec.de>
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On 14/09/23 17:43, Wadim Egorov wrote:
> DMAs are optional. Even if the DMA request is unsuccessfully,
> the ADC can still work properly.
> Make tiadc_request_dma() not fail if we do not provide dmas &
> dma-names properties.
>
> This actually fixes the wrong error handling of the tiadc_request_dma()
> result where the probing only failed if -EPROPE_DEFER was returned.
>
> Fixes: f438b9da75eb ("drivers: iio: ti_am335x_adc: add dma support")
>
> Signed-off-by: Wadim Egorov <w.egorov@phytec.de>
> ---
>  drivers/iio/adc/ti_am335x_adc.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c
> index 8db7a01cb5fb..e14aa9254ab1 100644
> --- a/drivers/iio/adc/ti_am335x_adc.c
> +++ b/drivers/iio/adc/ti_am335x_adc.c
> @@ -543,8 +543,11 @@ static int tiadc_request_dma(struct platform_device *pdev,
>  	if (IS_ERR(dma->chan)) {
>  		int ret = PTR_ERR(dma->chan);
>
> +		if (ret != -ENODEV)

Hi Wadim, Thanks for adding this fix but now there is no deferred probe

mechanism available here for the driver. We need to include that as well.

Regards

~B-Kapoor

> +			return dev_err_probe(&pdev->dev, ret,
> +					     "RX DMA channel request failed\n");
>  		dma->chan = NULL;
> -		return ret;
> +		return 0;
>  	}
>
>  	/* RX buffer */
> @@ -670,7 +673,7 @@ 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)
>  		goto err_dma;
>
>  	return 0;
> --
> 2.25.1
>
>
>