Re: [rtc-linux] Re: BUG: rtc: rtc_device_unregister() broken in 3.10-rcN

From: Alexander Holler
Date: Tue Jun 18 2013 - 14:22:56 EST


Am 18.06.2013 03:59, schrieb Jingoo Han:
On Tuesday, June 18, 2013 12:40 AM, Alexander Holler wrote:
Am 14.06.2013 19:19, schrieb Alexander Holler:
Hello,

I've just tested some things with 3.10-rc5+ and discovered that
rtc_device_unregister is broken. This is most likely because of the
switch to devm*. As 3.10 is already at -rc5, I'm posting this without

CC'ed Dmitry Torokhov, Sachin Kamat


Hi Alexander,

You are using 'drivers/rtc/rtc-hid-sensor-time.c', right?
If so, would you revert '479243b rtc: hid-sensor-time: use devm_rtc_device_register()',
and give the result?


Hi Dmitry, Sachin,
You can see the kernel debug message, when the problem happens.
(http://lists-archives.com/linux-kernel/27855385-bug-rtc-rtc_unregister_device-broken-in-3-10-rcn.html)


I've found the problem. Somehow I managed it with a patch i posted recently (3/9) to get the rtc_device_unregister() back into the remove-function of rtc-hid-sensor-time. Might be happend when rebasing the patch from 3.9.x to 3.10 or similiar, I don't know or remember.

I haven't seen it, because the backtrace doesn't show it. So what happend was likely:

remove -> rtc_device_unregister() (ok)
device remove -> devm -> rtc_device_unregister() (again) -> Crash.

Sorry for the noise.

Regards,

Alexander Holler
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