Subject: Re: [RFC][PATCH] alarmtimers: Handle late rtc module loading
From: John Stultz <john.stultz@linaro.org>
To: Meelis Roos <mroos@ut.ee>
Cc: Linux Kernel list <linux-kernel@vger.kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>
In-Reply-To: <alpine.SOC.1.00.1106171112460.29700@math.ut.ee>
References: <1308274479-25259-1-git-send-email-john.stultz@linaro.org>
	 <alpine.SOC.1.00.1106171112460.29700@math.ut.ee>
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Date: Fri, 17 Jun 2011 11:33:36 -0700
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On Fri, 2011-06-17 at 12:43 +0300, Meelis Roos wrote:
> > Meelis: Could you give this patch a shot to make sure it resolves
> > the issues you've seen on x86 and sparc?
> 
> Worked on sparc64 (Netra X1) on all 3 boots, on top of 
> 3.0.0-rc3-00202-geb96c92.
> 
> One the PC, I get the following about RTC in dmesg:
> 
> [    0.319145] drivers/rtc/hctosys.c: unable to open rtc device (rtc0)
> [    3.614132] rtc_cmos 00:03: RTC can wake from S4
> [    3.614480] rtc_cmos 00:03: rtc core: registered rtc_cmos as rtc0
> [    3.614582] rtc0: alarms up to one year, y3k, 114 bytes nvram

I'll double check, but I suspect that "unable to open rtc device"
message isn't new. The issue is that the rtc_cmos driver is built as a
module, and the hctosys functionality is running before the module is
loaded.

Hmmm. This maybe points to the need for some sort of callback system for
when RTC devices are registered. Since most existing code is just hoping
its available by late_init.

Thanks so much for the testing!

thanks
-john


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