[PATCH 04/11] rtc: at91rm9200: remove race condition

From: Alexandre Belloni
Date: Thu Jul 06 2017 - 05:45:07 EST


While highly unlikely, it is possible to get an interrupt as soon as it is
requested. In that case, at91_rtc_interrupt() will be called with rtc ==
NULL.

Solve that by using devm_rtc_allocate_device/rtc_register_device.

Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx>
---
drivers/rtc/rtc-at91rm9200.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c
index b60fd477778f..e221b78b6f10 100644
--- a/drivers/rtc/rtc-at91rm9200.c
+++ b/drivers/rtc/rtc-at91rm9200.c
@@ -409,6 +409,11 @@ static int __init at91_rtc_probe(struct platform_device *pdev)
return -ENOMEM;
}

+ rtc = devm_rtc_allocate_device(&pdev->dev);
+ if (IS_ERR(rtc))
+ return PTR_ERR(rtc);
+ platform_set_drvdata(pdev, rtc);
+
sclk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(sclk))
return PTR_ERR(sclk);
@@ -441,13 +446,10 @@ static int __init at91_rtc_probe(struct platform_device *pdev)
if (!device_can_wakeup(&pdev->dev))
device_init_wakeup(&pdev->dev, 1);

- rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
- &at91_rtc_ops, THIS_MODULE);
- if (IS_ERR(rtc)) {
- ret = PTR_ERR(rtc);
+ rtc->ops = &at91_rtc_ops;
+ ret = rtc_register_device(rtc);
+ if (ret)
goto err_clk;
- }
- platform_set_drvdata(pdev, rtc);

/* enable SECEV interrupt in order to initialize at91_rtc_upd_rdy
* completion.
--
2.11.0