@@ -375,21 +375,16 @@ static int at91_rtc_probe(struct platform_device *pdev)
return -ENOMEM;
}
- rtc->sclk = devm_clk_get(&pdev->dev, NULL);
- if (IS_ERR(rtc->sclk))
+ rtc->sclk = devm_clk_get_enabled(&pdev->dev, NULL);
+ if (IS_ERR(rtc->sclk)) {
+ dev_err(&pdev->dev, "Could not get and enable slow clock\n");
return PTR_ERR(rtc->sclk);
-
- ret = clk_prepare_enable(rtc->sclk);
- if (ret) {
- dev_err(&pdev->dev, "Could not enable slow clock\n");
- return ret;
}
sclk_rate = clk_get_rate(rtc->sclk);
if (!sclk_rate || sclk_rate > AT91_RTT_RTPRES) {
dev_err(&pdev->dev, "Invalid slow clock rate\n");
- ret = -EINVAL;
- goto err_clk;
+ return -EINVAL;
}
mr = rtt_readl(rtc, MR);
@@ -405,10 +400,8 @@ static int at91_rtc_probe(struct platform_device *pdev)
rtt_writel(rtc, MR, mr);
rtc->rtcdev = devm_rtc_allocate_device(&pdev->dev);
- if (IS_ERR(rtc->rtcdev)) {
- ret = PTR_ERR(rtc->rtcdev);
- goto err_clk;
- }
+ if (IS_ERR(rtc->rtcdev))
+ return PTR_ERR(rtc->rtcdev);
rtc->rtcdev->ops = &at91_rtc_ops;
rtc->rtcdev->range_max = U32_MAX;
@@ -419,7 +412,7 @@ static int at91_rtc_probe(struct platform_device *pdev)
dev_name(&rtc->rtcdev->dev), rtc);
if (ret) {
dev_dbg(&pdev->dev, "can't share IRQ %d?\n", rtc->irq);
- goto err_clk;
+ return ret;
}
/* NOTE: sam9260 rev A silicon has a ROM bug which resets the
@@ -433,11 +426,6 @@ static int at91_rtc_probe(struct platform_device *pdev)
dev_name(&rtc->rtcdev->dev));
return devm_rtc_register_device(rtc->rtcdev);
-
-err_clk:
- clk_disable_unprepare(rtc->sclk);
-
- return ret;
}
/*
@@ -450,8 +438,6 @@ static void at91_rtc_remove(struct platform_device *pdev)
/* disable all interrupts */
rtt_writel(rtc, MR, mr & ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN));
-
- clk_disable_unprepare(rtc->sclk);
}
static void at91_rtc_shutdown(struct platform_device *pdev)
If rtc->sclk was enabled in at91_rtc_probe(), it must be disabled in all error paths to ensure proper cleanup. However, if devm_rtc_register_device() returns an error in at91_rtc_probe(), the rtc->sclk clock will not be disabled. Use the devm_clk_get_enabled() helper function to ensure proper call balance for rtc->sclk. Found by Linux Verification Center (linuxtesting.org) with Klever. Fixes: a975f47f6e9a ("rtc: at91sam9: use clk API instead of relying on AT91_SLOW_CLOCK") Signed-off-by: Vitalii Mordan <mordan@ispras.ru> --- drivers/rtc/rtc-at91sam9.c | 28 +++++++--------------------- 1 file changed, 7 insertions(+), 21 deletions(-)