diff options
| author | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2026-06-25 15:02:00 +0200 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2026-08-19 18:11:38 +0200 |
| commit | bcad3667a33750905fbb7470de5727bf8e37186d (patch) | |
| tree | 4472f1cc67ddc9a2005f61e3496e0877cf132dcd /drivers/rtc | |
| parent | 7490b8356e52e09c196645912f2c054f79aa5f3a (diff) | |
rtc: mv: fix potential race condition
Since the driver allocates the IRQ using devm_request_irq(), this means the
IRQ is going to be automatically unregistered by devres after
mv_rtc_remove() returns.
However, mv_rtc_remove() explicitly disables the hardware clock before
devres teardown happens so the interrupt handler may run while the clock is
disabled leading to a possible bus hang when accessing registers.
Link: https://patch.msgid.link/20260625130202.1621692-1-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/rtc-mv.c | 22 |
1 files changed, 6 insertions, 16 deletions
diff --git a/drivers/rtc/rtc-mv.c b/drivers/rtc/rtc-mv.c index f88976fd6d5d..c0f1bcd838e3 100644 --- a/drivers/rtc/rtc-mv.c +++ b/drivers/rtc/rtc-mv.c @@ -219,17 +219,15 @@ 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); - /* Not all SoCs require a clock.*/ - if (!IS_ERR(pdata->clk)) - clk_prepare_enable(pdata->clk); + pdata->clk = devm_clk_get_optional_prepared(&pdev->dev, NULL); + if (IS_ERR(pdata->clk)) + return PTR_ERR(pdata->clk); /* 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 +236,7 @@ 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 +246,7 @@ 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) { @@ -275,9 +271,6 @@ 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; } @@ -288,9 +281,6 @@ static void __exit mv_rtc_remove(struct platform_device *pdev) if (pdata->irq >= 0) device_init_wakeup(&pdev->dev, false); - - if (!IS_ERR(pdata->clk)) - clk_disable_unprepare(pdata->clk); } #ifdef CONFIG_OF |