Re: [PATCH v2 3/7] rtc: mt6397: improvements of rtc driver

Alexandre Belloni
2019-07-04T20:43:36Z

On 03/07/2019 18:48:18+0200, Frank Wunderlich wrote:
> @@ -271,14 +268,11 @@ static int mtk_rtc_probe(struct platform_device *pdev)
>
> platform_set_drvdata(pdev, rtc);
>
> - rtc->rtc_dev = devm_rtc_allocate_device(rtc->dev);
> - if (IS_ERR(rtc->rtc_dev))
> - return PTR_ERR(rtc->rtc_dev);
> + ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
> + mtk_rtc_irq_handler_thread,
> + IRQF_ONESHOT | IRQF_TRIGGER_HIGH,
> + "mt6397-rtc", rtc);
>

This change may lead to a crash and the allocation was intentionally
placed before the irq request.

> - ret = request_threaded_irq(rtc->irq, NULL,
> - mtk_rtc_irq_handler_thread,
> - IRQF_ONESHOT | IRQF_TRIGGER_HIGH,
> - "mt6397-rtc", rtc);
> if (ret) {
> dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
> rtc->irq, ret);
> @@ -287,6 +281,10 @@ static int mtk_rtc_probe(struct platform_device *pdev)
>
> device_init_wakeup(&pdev->dev, 1);
>
> + rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
> + if (IS_ERR(rtc->rtc_dev))
> + return PTR_ERR(rtc->rtc_dev);
> +
> rtc->rtc_dev->ops = &mtk_rtc_ops;
>
> ret = rtc_register_device(rtc->rtc_dev);
> @@ -302,15 +300,6 @@ static int mtk_rtc_probe(struct platform_device *pdev)
> return ret;
> }
>
> -static int mtk_rtc_remove(struct platform_device *pdev)
> -{
> - struct mt6397_rtc *rtc = platform_get_drvdata(pdev);
> -
> - free_irq(rtc->irq, rtc);
> -
> - return 0;
> -}
> -
> #ifdef CONFIG_PM_SLEEP
> static int mt6397_rtc_suspend(struct device *dev)
> {
> @@ -337,6 +326,7 @@ static SIMPLE_DEV_PM_OPS(mt6397_pm_ops, mt6397_rtc_suspend,
> mt6397_rtc_resume);
>
> static const struct of_device_id mt6397_rtc_of_match[] = {
> + { .compatible = "mediatek,mt6323-rtc", },

Unrelated change, this is not an improvement and must be accompanied by
a documentation change.

> { .compatible = "mediatek,mt6397-rtc", },
> { }
> };
> @@ -349,7 +339,6 @@ static struct platform_driver mtk_rtc_driver = {
> .pm = &mt6397_pm_ops,
> },
> .probe = mtk_rtc_probe,
> - .remove = mtk_rtc_remove,
> };
>
> module_platform_driver(mtk_rtc_driver);
> --
> 2.17.1
>

--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering