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Subject: Re: [PATCH v2 06/18] iio: adc: meson_saradc: Simplify with dev_err_probe()

2020-08-27 19:51:11

by Andy Shevchenko

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Subject: Re: [PATCH v2 05/18] iio: adc: ltc2497: Simplify with dev_err_probe()

2020-08-27 19:51:19

by Andy Shevchenko

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Subject: Re: [PATCH v2 07/18] iio: adc: rcar-gyroadc: Simplify with dev_err_probe()

2020-08-27 19:52:53

by Andy Shevchenko

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Subject: Re: [PATCH v2 08/18] iio: adc: stm32: Simplify with dev_err_probe()

On Thu, Aug 27, 2020 at 10:28 PM Krzysztof Kozlowski <[email protected]> wrote:
>
> Common pattern of handling deferred probe can be simplified with
> dev_err_probe(). Less code and also it prints the error value.

Reviewed-by: Andy Shevchenko <[email protected]>

> Signed-off-by: Krzysztof Kozlowski <[email protected]>
>
> ---
>
> Changes since v1:
> 1. Convert to devm_clk_get_optional
> 2. Update also stm32-dfsdm-core and stm32-dac-core.
> 3. Wrap around 100 characters (accepted by checkpatch).
> ---
> drivers/iio/adc/stm32-adc-core.c | 67 +++++++++---------------------
> drivers/iio/adc/stm32-adc.c | 9 +---
> drivers/iio/adc/stm32-dfsdm-adc.c | 9 +---
> drivers/iio/adc/stm32-dfsdm-core.c | 8 +---
> drivers/iio/dac/stm32-dac-core.c | 5 +--
> 5 files changed, 26 insertions(+), 72 deletions(-)
>
> diff --git a/drivers/iio/adc/stm32-adc-core.c b/drivers/iio/adc/stm32-adc-core.c
> index 0e2068ec068b..707c85dab7df 100644
> --- a/drivers/iio/adc/stm32-adc-core.c
> +++ b/drivers/iio/adc/stm32-adc-core.c
> @@ -582,11 +582,9 @@ static int stm32_adc_core_switches_probe(struct device *dev,
> priv->syscfg = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
> if (IS_ERR(priv->syscfg)) {
> ret = PTR_ERR(priv->syscfg);
> - if (ret != -ENODEV) {
> - if (ret != -EPROBE_DEFER)
> - dev_err(dev, "Can't probe syscfg: %d\n", ret);
> - return ret;
> - }
> + if (ret != -ENODEV)
> + return dev_err_probe(dev, ret, "Can't probe syscfg\n");
> +
> priv->syscfg = NULL;
> }
>
> @@ -596,12 +594,9 @@ static int stm32_adc_core_switches_probe(struct device *dev,
> priv->booster = devm_regulator_get_optional(dev, "booster");
> if (IS_ERR(priv->booster)) {
> ret = PTR_ERR(priv->booster);
> - if (ret != -ENODEV) {
> - if (ret != -EPROBE_DEFER)
> - dev_err(dev, "can't get booster %d\n",
> - ret);
> - return ret;
> - }
> + if (ret != -ENODEV)
> + dev_err_probe(dev, ret, "can't get booster\n");
> +
> priv->booster = NULL;
> }
> }
> @@ -612,11 +607,9 @@ static int stm32_adc_core_switches_probe(struct device *dev,
> priv->vdd = devm_regulator_get_optional(dev, "vdd");
> if (IS_ERR(priv->vdd)) {
> ret = PTR_ERR(priv->vdd);
> - if (ret != -ENODEV) {
> - if (ret != -EPROBE_DEFER)
> - dev_err(dev, "can't get vdd %d\n", ret);
> - return ret;
> - }
> + if (ret != -ENODEV)
> + return dev_err_probe(dev, ret, "can't get vdd\n");
> +
> priv->vdd = NULL;
> }
> }
> @@ -669,42 +662,20 @@ static int stm32_adc_probe(struct platform_device *pdev)
> priv->common.phys_base = res->start;
>
> priv->vdda = devm_regulator_get(&pdev->dev, "vdda");
> - if (IS_ERR(priv->vdda)) {
> - ret = PTR_ERR(priv->vdda);
> - if (ret != -EPROBE_DEFER)
> - dev_err(&pdev->dev, "vdda get failed, %d\n", ret);
> - return ret;
> - }
> + if (IS_ERR(priv->vdda))
> + return dev_err_probe(&pdev->dev, PTR_ERR(priv->vdda), "vdda get failed\n");
>
> priv->vref = devm_regulator_get(&pdev->dev, "vref");
> - if (IS_ERR(priv->vref)) {
> - ret = PTR_ERR(priv->vref);
> - if (ret != -EPROBE_DEFER)
> - dev_err(&pdev->dev, "vref get failed, %d\n", ret);
> - return ret;
> - }
> + if (IS_ERR(priv->vref))
> + return dev_err_probe(&pdev->dev, PTR_ERR(priv->vref), "vref get failed\n");
>
> - priv->aclk = devm_clk_get(&pdev->dev, "adc");
> - if (IS_ERR(priv->aclk)) {
> - ret = PTR_ERR(priv->aclk);
> - if (ret != -ENOENT) {
> - if (ret != -EPROBE_DEFER)
> - dev_err(&pdev->dev, "Can't get 'adc' clock\n");
> - return ret;
> - }
> - priv->aclk = NULL;
> - }
> + priv->aclk = devm_clk_get_optional(&pdev->dev, "adc");
> + if (IS_ERR(priv->aclk))
> + return dev_err_probe(&pdev->dev, PTR_ERR(priv->aclk), "Can't get 'adc' clock\n");
>
> - priv->bclk = devm_clk_get(&pdev->dev, "bus");
> - if (IS_ERR(priv->bclk)) {
> - ret = PTR_ERR(priv->bclk);
> - if (ret != -ENOENT) {
> - if (ret != -EPROBE_DEFER)
> - dev_err(&pdev->dev, "Can't get 'bus' clock\n");
> - return ret;
> - }
> - priv->bclk = NULL;
> - }
> + priv->bclk = devm_clk_get_optional(&pdev->dev, "bus");
> + if (IS_ERR(priv->bclk))
> + return dev_err_probe(&pdev->dev, PTR_ERR(priv->bclk), "Can't get 'bus' clock\n");
>
> ret = stm32_adc_core_switches_probe(dev, priv);
> if (ret)
> diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
> index 3eb9ebe8372f..b8e764ca54a6 100644
> --- a/drivers/iio/adc/stm32-adc.c
> +++ b/drivers/iio/adc/stm32-adc.c
> @@ -1805,13 +1805,8 @@ static int stm32_adc_dma_request(struct device *dev, struct iio_dev *indio_dev)
> 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;
> - }
> + if (ret != -ENODEV)
> + return dev_err_probe(dev, ret, "DMA channel request failed with\n");
>
> /* DMA is optional: fall back to IRQ mode */
> adc->dma_chan = NULL;
> diff --git a/drivers/iio/adc/stm32-dfsdm-adc.c b/drivers/iio/adc/stm32-dfsdm-adc.c
> index 5e10fb4f3704..12c951078c1f 100644
> --- a/drivers/iio/adc/stm32-dfsdm-adc.c
> +++ b/drivers/iio/adc/stm32-dfsdm-adc.c
> @@ -1473,13 +1473,8 @@ static int stm32_dfsdm_adc_init(struct device *dev, struct iio_dev *indio_dev)
> /* Optionally request DMA */
> ret = stm32_dfsdm_dma_request(dev, indio_dev);
> if (ret) {
> - if (ret != -ENODEV) {
> - if (ret != -EPROBE_DEFER)
> - dev_err(dev,
> - "DMA channel request failed with %d\n",
> - ret);
> - return ret;
> - }
> + if (ret != -ENODEV)
> + return dev_err_probe(dev, ret, "DMA channel request failed with\n");
>
> dev_dbg(dev, "No DMA support\n");
> return 0;
> diff --git a/drivers/iio/adc/stm32-dfsdm-core.c b/drivers/iio/adc/stm32-dfsdm-core.c
> index 26e2011c5868..34e4e6e59acf 100644
> --- a/drivers/iio/adc/stm32-dfsdm-core.c
> +++ b/drivers/iio/adc/stm32-dfsdm-core.c
> @@ -243,12 +243,8 @@ static int stm32_dfsdm_parse_of(struct platform_device *pdev,
> * on use case.
> */
> priv->clk = devm_clk_get(&pdev->dev, "dfsdm");
> - if (IS_ERR(priv->clk)) {
> - ret = PTR_ERR(priv->clk);
> - if (ret != -EPROBE_DEFER)
> - dev_err(&pdev->dev, "Failed to get clock (%d)\n", ret);
> - return ret;
> - }
> + if (IS_ERR(priv->clk))
> + return dev_err_probe(&pdev->dev, PTR_ERR(priv->clk), "Failed to get clock\n");
>
> priv->aclk = devm_clk_get(&pdev->dev, "audio");
> if (IS_ERR(priv->aclk))
> diff --git a/drivers/iio/dac/stm32-dac-core.c b/drivers/iio/dac/stm32-dac-core.c
> index 7e5809ba0dee..906436780347 100644
> --- a/drivers/iio/dac/stm32-dac-core.c
> +++ b/drivers/iio/dac/stm32-dac-core.c
> @@ -150,10 +150,7 @@ static int stm32_dac_probe(struct platform_device *pdev)
> rst = devm_reset_control_get_optional_exclusive(dev, NULL);
> if (rst) {
> if (IS_ERR(rst)) {
> - ret = PTR_ERR(rst);
> - if (ret != -EPROBE_DEFER)
> - dev_err(dev, "reset get failed, %d\n", ret);
> -
> + ret = dev_err_probe(dev, PTR_ERR(rst), "reset get failed\n");
> goto err_hw_stop;
> }
>
> --
> 2.17.1
>

--
With Best Regards,
Andy Shevchenko

On Fri, 2020-08-28 at 11:39 +0200, Peter Rosin wrote:
> On 2020-08-28 09:03, Krzysztof Kozlowski wrote:
> > > > If there is no consensus among discussing people, I find this 100 line
> > > > more readable, already got review, checkpatch accepts it so if subsystem
> > > > maintainer likes it, I prefer to leave it like this.
> > >
> > > I'm not impressed by that argument. For the files I have mentioned, it
> > > does not matter very much to me if you and some random person think that
> > > 100 columns might *slightly* improve readability.
> > >
> > > Quoting coding-style
> > >
> > > Statements longer than 80 columns should be broken into sensible chunks,
> > > unless exceeding 80 columns significantly increases readability and does
> > > not hide information.
> > >
> > > Notice that word? *significantly*
> >
> > Notice also checkpatch change...
>
> How is that relevant? checkpatch has *never* had the final say and its
> heuristics can never be perfect. Meanwhile, coding style is talking about
> exactly the case under discussion, and agrees with me perfectly.

As the checkpatch maintainer, checkpatch is stupid.
Using it as a primary argument should never be acceptable.

But line lengths from 81 to 100 columns should be exceptions
rather than
standard use.

Any named maintainer of actual code determines the style for
that code.

Style consistency and use of kernel standard mechanisms
should be the primary goals here.