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rtc: ds1685: fix possible race condition 

The IRQ is requested before the struct rtc is allocated and registered, but
this struct is used in the IRQ handler.

Switch to devm_rtc_allocate_device/rtc_register_device to allocate the rtc
before requesting the IRQ.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
Alexandre Belloni 2018-05-31 11:56:42 +02:00
parent a0defd7cfc
commit a2ae8323a8
1 changed files with 18 additions and 23 deletions
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41
drivers/rtc/rtc-ds1685.c
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@ -2037,6 +2037,22 @@ ds1685_rtc_probe(struct platform_device *pdev)
rtc->write(rtc, RTC_EXT_CTRL_4B,
(rtc->read(rtc, RTC_EXT_CTRL_4B) | RTC_CTRL_4B_KSE));
rtc_dev = devm_rtc_allocate_device(&pdev->dev);
if (IS_ERR(rtc_dev))
return PTR_ERR(rtc_dev);
rtc_dev->ops = &ds1685_rtc_ops;
/* Maximum periodic rate is 8192Hz (0.122070ms). */
rtc_dev->max_user_freq = RTC_MAX_USER_FREQ;
/* See if the platform doesn't support UIE. */
if (pdata->uie_unsupported)
rtc_dev->uie_unsupported = 1;
rtc->uie_unsupported = pdata->uie_unsupported;
rtc->dev = rtc_dev;
/*
* Fetch the IRQ and setup the interrupt handler.
*
@ -2069,32 +2085,13 @@ ds1685_rtc_probe(struct platform_device *pdev)
/* Setup complete. */
ds1685_rtc_switch_to_bank0(rtc);
/* Register the device as an RTC. */
rtc_dev = rtc_device_register(pdev->name, &pdev->dev,
&ds1685_rtc_ops, THIS_MODULE);
/* Success? */
if (IS_ERR(rtc_dev))
return PTR_ERR(rtc_dev);
/* Maximum periodic rate is 8192Hz (0.122070ms). */
rtc_dev->max_user_freq = RTC_MAX_USER_FREQ;
/* See if the platform doesn't support UIE. */
if (pdata->uie_unsupported)
rtc_dev->uie_unsupported = 1;
rtc->uie_unsupported = pdata->uie_unsupported;
rtc->dev = rtc_dev;
#ifdef CONFIG_SYSFS
ret = ds1685_rtc_sysfs_register(&pdev->dev);
if (ret)
rtc_device_unregister(rtc->dev);
return ret;
#endif
/* Done! */
return ret;
return rtc_register_device(rtc_dev);
}
/**
@ -2110,8 +2107,6 @@ ds1685_rtc_remove(struct platform_device *pdev)
ds1685_rtc_sysfs_unregister(&pdev->dev);
#endif
rtc_device_unregister(rtc->dev);
/* Read Ctrl B and clear PIE/AIE/UIE. */
rtc->write(rtc, RTC_CTRL_B,
(rtc->read(rtc, RTC_CTRL_B) &