rtc: at91rm9200: remove race condition

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@free-electrons.com>

diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c
index b60fd477778f7fed1e8c1a510d80646f47d8373f..e221b78b6f106ec3ccde7c3326b5934c48153f9c 100644 (file)
--- 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.