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charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 09/08/2023 04:10:27+0200, Alexandre Belloni wrote: > > +static int ma35d1_rtc_probe(struct platform_device *pdev) > > +{ > > + struct ma35_rtc *rtc; > > + struct clk *clk; > > + u32 regval; > > + int err; > > + > > + rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); > > + if (!rtc) > > + return -ENOMEM; > > + > > + rtc->rtc_reg = devm_platform_ioremap_resource(pdev, 0); > > + if (IS_ERR(rtc->rtc_reg)) > > + return PTR_ERR(rtc->rtc_reg); > > + > > + clk = of_clk_get(pdev->dev.of_node, 0); > > + if (IS_ERR(clk)) > > + return dev_err_probe(&pdev->dev, PTR_ERR(clk), "failed to find rtc clock\n"); > > + > > + err = clk_prepare_enable(clk); > > + if (err) > > + return -ENOENT; > > + > > + platform_set_drvdata(pdev, rtc); > > + > > + rtc->rtcdev = devm_rtc_device_register(&pdev->dev, pdev->name, > > + &ma35d1_rtc_ops, THIS_MODULE); > > + if (IS_ERR(rtc->rtcdev)) > > + return dev_err_probe(&pdev->dev, PTR_ERR(rtc->rtcdev), > > + "failed to register rtc device\n"); > > This MUST be done last in probe, else you open a race with userspace. > > > > + > > + err = ma35d1_rtc_init(rtc, RTC_INIT_TIMEOUT); > > + if (err) > > + return err; > > + > > I don't believe you should do this on every probe but only when this > hasn't been done yet. > Also, if you can know that the time has never been set, don't discard this information, this is crucial information and it needs to be reported to userspace. -- Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel