On 20/07/2023 22:08:14+0800, Yuanjun Gong wrote:
> in mv_rtc_probe(), the return value of function
> clk_prepare_enable() should be checked, since it may fail.
> using devm_clk_get_enabled() instead of devm_clk_get() and
> clk_prepare_enable() can avoid this problem.
>
> Signed-off-by: Yuanjun Gong <ruc_gongyuanjun@xxxxxxx>
> ---
> drivers/rtc/rtc-mv.c | 20 ++++++--------------
> 1 file changed, 6 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/rtc/rtc-mv.c b/drivers/rtc/rtc-mv.c
> index 6c526e2ec56d..8cd33721be03 100644
> --- a/drivers/rtc/rtc-mv.c
> +++ b/drivers/rtc/rtc-mv.c
> @@ -219,17 +219,16 @@ static int __init mv_rtc_probe(struct platform_device *pdev)
> if (IS_ERR(pdata->ioaddr))
> return PTR_ERR(pdata->ioaddr);
>
> - pdata->clk = devm_clk_get(&pdev->dev, NULL);
> + pdata->clk = devm_clk_get_enabled(&pdev->dev, NULL);
> /* Not all SoCs require a clock.*/
> - if (!IS_ERR(pdata->clk))
> - clk_prepare_enable(pdata->clk);
> + if (IS_ERR(pdata->clk))
> + return PTR_ERR(pdata->clk);
Look at the comment, "Not all SoCs require a clock.", you are breaking
the driver for multiple platforms.
>
> /* make sure the 24 hour mode is enabled */
> rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
> if (rtc_time & RTC_HOURS_12H_MODE) {
> dev_err(&pdev->dev, "12 Hour mode is enabled but not supported.\n");
> - ret = -EINVAL;
> - goto out;
> + return -EINVAL;
> }
>
> /* make sure it is actually functional */
> @@ -238,8 +237,7 @@ static int __init mv_rtc_probe(struct platform_device *pdev)
> rtc_time = readl(pdata->ioaddr + RTC_TIME_REG_OFFS);
> if (rtc_time == 0x01000000) {
> dev_err(&pdev->dev, "internal RTC not ticking\n");
> - ret = -ENODEV;
> - goto out;
> + return -ENODEV;
> }
> }
>
> @@ -249,8 +247,7 @@ static int __init mv_rtc_probe(struct platform_device *pdev)
>
> pdata->rtc = devm_rtc_allocate_device(&pdev->dev);
> if (IS_ERR(pdata->rtc)) {
> - ret = PTR_ERR(pdata->rtc);
> - goto out;
> + return PTR_ERR(pdata->rtc);
> }
>
> if (pdata->irq >= 0) {
> @@ -275,11 +272,6 @@ static int __init mv_rtc_probe(struct platform_device *pdev)
> ret = devm_rtc_register_device(pdata->rtc);
> if (!ret)
> return 0;
> -out:
> - if (!IS_ERR(pdata->clk))
> - clk_disable_unprepare(pdata->clk);
> -
> - return ret;
> }
>
> static int __exit mv_rtc_remove(struct platform_device *pdev)
> --
> 2.17.1
>
--
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
