linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: "Leizhen (ThunderTown)" <thunder.leizhen@huawei.com>
To: Arnd Bergmann <arnd@arndb.de>, <linux-arm-kernel@lists.infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will.deacon@arm.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	Kefeng Wang <wangkefeng.wang@huawei.com>,
	Xinwei Hu <huxinwei@huawei.com>, Zefan Li <lizefan@huawei.com>,
	Tianhong Ding <dingtianhong@huawei.com>,
	Hanjun Guo <guohanjun@huawei.com>
Subject: Re: [PATCH 2/2] arm64: to allow EFI_RTC can be selected on ARM64
Date: Mon, 28 Sep 2015 16:29:57 +0800	[thread overview]
Message-ID: <5608FA85.8070009@huawei.com> (raw)
In-Reply-To: <1783631.jH4WY2RqXu@wuerfel>



On 2015/9/28 15:35, Arnd Bergmann wrote:
> On Monday 28 September 2015 13:34:38 Zhen Lei wrote:
>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
>> index 07d1811..25cec57 100644
>> --- a/arch/arm64/Kconfig
>> +++ b/arch/arm64/Kconfig
>> @@ -85,7 +85,7 @@ config ARM64
>>         select PERF_USE_VMALLOC
>>         select POWER_RESET
>>         select POWER_SUPPLY
>> -       select RTC_LIB
>> +       select RTC_LIB if !EFI
>>         select SPARSE_IRQ
>>         select SYSCTL_EXCEPTION_TRACE
>>         select HAVE_CONTEXT_TRACKING
> 
> Sorry, we can't do that: enabling EFI has to be done in a way that it only
> adds features but not disables them.

I run "make ARCH=arm64 menuconfig" and found that RTC_CLASS is selected by default. Actually, RTC_LIB only
controls whether to display some configs when run "make menuconfig". I list all informations below:

---------make ARCH=arm64 menuconfig-----
  [*] Real Time Clock  --->

---------drivers/rtc/Kconfig-------
menuconfig RTC_CLASS
        bool "Real Time Clock"
        default n
        depends on !S390 && !UML
        select RTC_LIB

-----------------------------------
find . -name "*Kconfig*" | xargs grep RTC_LIB
./drivers/rtc/Kconfig:config RTC_LIB
./drivers/rtc/Kconfig:	select RTC_LIB
./drivers/char/Kconfig:if RTC_LIB=n
./drivers/char/Kconfig:endif # RTC_LIB
./arch/x86/Kconfig:	select RTC_LIB
./arch/arm/Kconfig:	select RTC_LIB
./arch/arm64/Kconfig:	select RTC_LIB if !EFI
./arch/sh/Kconfig:	select RTC_LIB
./arch/mips/Kconfig:	select RTC_LIB if !MACH_LOONGSON64

--------------drivers/char/Kconfig--------------
if RTC_LIB=n

config RTC
        tristate "Enhanced Real Time Clock Support (legacy PC RTC driver)"

.......

endif # RTC_LIB


> 
> Your patch breaks RTC on all non-EFI platforms as soon as CONFIG_EFI
> is selected by the user.

No, on non-EFI platforms, they can still use RTC as before. As I mentioned above,
RTC_LIB only controls whether to display some configs when run "make menuconfig".
On ARM64, (in this patch) I only allowed EFI_RTC can be showed when RTC_LIB was not selected.

--------------drivers/char/Kconfig--------------
if RTC_LIB=n

config RTC
tristate "Enhanced Real Time Clock Support (legacy PC RTC driver)"

.......

config EFI_RTC
        bool "EFI Real Time Clock Services"
        depends on IA64 || ARM64

.......

endif # RTC_LIB

> 
> 	Arnd
> 
> .
> 


  reply	other threads:[~2015-09-28  8:34 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-09-28  5:34 [PATCH 0/2] to allow EFI_RTC can be selected on ARM64 Zhen Lei
2015-09-28  5:34 ` [PATCH 1/2] char/rtc: " Zhen Lei
2015-09-28  5:34 ` [PATCH 2/2] arm64: " Zhen Lei
2015-09-28  7:35   ` Arnd Bergmann
2015-09-28  8:29     ` Leizhen (ThunderTown) [this message]
2015-09-28  8:42       ` Arnd Bergmann
2015-09-28  9:44         ` Leizhen (ThunderTown)
2015-09-28  9:56           ` Arnd Bergmann
2015-10-08  9:07           ` Leizhen (ThunderTown)
2015-09-28  7:40   ` Ard Biesheuvel
2015-09-28  8:41     ` Leizhen (ThunderTown)

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=5608FA85.8070009@huawei.com \
    --to=thunder.leizhen@huawei.com \
    --cc=arnd@arndb.de \
    --cc=catalin.marinas@arm.com \
    --cc=dingtianhong@huawei.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=guohanjun@huawei.com \
    --cc=huxinwei@huawei.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=lizefan@huawei.com \
    --cc=wangkefeng.wang@huawei.com \
    --cc=will.deacon@arm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).