From mboxrd@z Thu Jan 1 00:00:00 1970 From: joeyli Subject: Re: [RFC PATCH 06/14] rtc-efi: register rtc-efi device when EFI enabled Date: Fri, 20 Dec 2013 12:24:51 +0800 Message-ID: <1387513491.3539.4345.camel@linux-s257.site> References: <1387439515-8926-1-git-send-email-jlee@suse.com> <1387439515-8926-7-git-send-email-jlee@suse.com> <20131219140918.GF3145@console-pimps.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20131219140918.GF3145@console-pimps.org> Sender: linux-acpi-owner@vger.kernel.org To: Matt Fleming Cc: "Rafael J. Wysocki" , Alessandro Zummo , "H. Peter Anvin" , Matthew Garrett , Elliott@hp.com, samer.el-haj-mahmoud@hp.com, Oliver Neukum , werner@suse.com, trenn@suse.de, JBeulich@suse.com, linux-kernel@vger.kernel.org, rtc-linux@googlegroups.com, x86@kernel.org, "linux-efi@vger.kernel.org" , linux-acpi@vger.kernel.org, Matt Fleming , Thomas Gleixner , Ingo Molnar List-Id: linux-efi@vger.kernel.org =E6=96=BC =E5=9B=9B=EF=BC=8C2013-12-19 =E6=96=BC 14:09 +0000=EF=BC=8CMa= tt Fleming =E6=8F=90=E5=88=B0=EF=BC=9A > On Thu, 19 Dec, at 03:51:47PM, Lee, Chun-Yi wrote: > > UEFI time services, GetTime(), SetTime(), GetWakeupTime(), SetWakeu= pTime() are also > > supported by other non-IA64 architecutre with UEFI BIOS, e.g. x86. > >=20 > > This patch changed RTC_DRV_EFI configuration to depend on EFI but n= ot just IA64. It > > checks efi_enabled flag and efi-rtc driver should enabled. > >=20 > > Cc: Matt Fleming > > Cc: H. Peter Anvin > > Cc: Matthew Garrett > > Cc: Thomas Gleixner > > Cc: Ingo Molnar > > Cc: Jan Beulich > > Signed-off-by: Lee, Chun-Yi > > --- > > arch/x86/platform/efi/efi.c | 17 +++++++++++++++++ > > drivers/rtc/Kconfig | 2 +- > > 2 files changed, 18 insertions(+), 1 deletions(-) >=20 > This patch needs to be justified. Enabling the EFI runtime *Time > functions just because they're available isn't good enough. We need t= o > know why this patch improves things, what use case does it solve? >=20 The main purpose of enable efi-rtc driver is providing interface to userspace access timezone field in EFI time services. Currently have two BIOS interfaces provided the timezone field accessin= g ability, ACPI TAD and EFI. I hope can enable them on x86_64 machines. > The general attitude has been that we want to invoke the runtime > services less, not more, due to the huge variety of runtime > implementation bugs. >=20 I agreed, but userspace application should not be too often to access RTC. Maybe only when system boot and set timezone. Thanks a lot! Joey Lee -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html