From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Salter Subject: Re: [PATCH] rtc: Disable EFI rtc for x86 Date: Fri, 03 Oct 2014 11:01:57 -0400 Message-ID: <1412348517.5410.13.camel@deneb.redhat.com> References: <1412339576-17972-1-git-send-email-matt@console-pimps.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1412339576-17972-1-git-send-email-matt-HNK1S37rvNbeXh+fF434Mdi2O/JbrIOy@public.gmane.org> Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Matt Fleming Cc: Alessandro Zummo , rtc-linux-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Matt Fleming , Dave Young List-Id: linux-efi@vger.kernel.org On Fri, 2014-10-03 at 13:32 +0100, Matt Fleming wrote: > From: Matt Fleming > > commit da167ad7638759 ("rtc: ia64: allow other architectures to use EFI > RTC") inadvertently introduced a regression for x86. We've been careful > not to enable the EFI rtc driver for x86 due to the generally buggy > implementations of the time-related EFI runtime services. > > Previous attempts have been made to us the time EFI services, but all > have eventually been reverted due to crashes inside the firmware code. > > In fact, since the above commit was merged we've seen reports of crashes > on 32-bit tablets, > > https://bugzilla.kernel.org/show_bug.cgi?id=84241#c21 > > Disable it explicitly for x86 so that we don't give users false hope > that this driver will work - it won't, and your machine is likely to > crash. > > Cc: Mark Salter > Cc: Dave Young > Cc: Alessandro Zummo > Signed-off-by: Matt Fleming > --- Acked-by: Mark Salter > > Unless anyone objects, I'm happy to take this through the EFI tree. > > drivers/rtc/Kconfig | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig > index a168e96142b9..54ef393b0def 100644 > --- a/drivers/rtc/Kconfig > +++ b/drivers/rtc/Kconfig > @@ -806,7 +806,7 @@ config RTC_DRV_DA9063 > > config RTC_DRV_EFI > tristate "EFI RTC" > - depends on EFI > + depends on EFI && !X86 > help > If you say yes here you will get support for the EFI > Real Time Clock.