Re: [PATCH] rtc: Disable EFI rtc for x86

Matt Fleming
2014-11-10T11:22:48Z

On Sun, 2014-11-09 at 19:22 +0100, Borislav Petkov wrote:
> On Sun, Nov 09, 2014 at 06:37:46PM +0100, Pali Rohár wrote:
> > this patch totally disabled efi rfc driver on x86 machines at
> > compile time. But on some x86 machines it working without crash
> > and reading from file /sys/class/rtc/rtc*/since_epoch returns
> > correct information. So why to disable compiling driver on
> > machines where driver working?
>
> Sounds like we need an efi=rtc_enable knob for people who what to use
> it...

I'm not so sure. By and large, the EFI runtime Time services just don't
work very well on x86. Just because they work sometimes, doesn't
actually mean it's a good idea to use them.

The one scenario where the time services are useful is early on during
boot when we want to get the timezone information. I have vague
recollections of someone working on that.