2014-04-13 19:06:37

by Stefani Seibold

[permalink] [raw]
Subject: X86: Impossible select Enhanced Real Time Clock Support (legacy PC RTC driver)

Since some kernel version it is impossible to select the Enhanced Real
Time Clock Support (legacy PC RTC driver) because RTC_LIB is set by
default in arch/x86/Kconfig, but the rule for selecting CONFIG_RTC is
RTC_LIB=n. So the code of driver/char/rtc is still useless.

This breaks the API since there is no more misc device /dev/rtc
available without a udev rule or a link to /dev/rtc0.


2014-04-21 17:58:55

by Randy Dunlap

[permalink] [raw]
Subject: Re: X86: Impossible select Enhanced Real Time Clock Support (legacy PC RTC driver)

[adding more patch committers]

On 04/13/2014 12:05 PM, Stefani Seibold wrote:
> Since some kernel version it is impossible to select the Enhanced Real
> Time Clock Support (legacy PC RTC driver) because RTC_LIB is set by
> default in arch/x86/Kconfig, but the rule for selecting CONFIG_RTC is
> RTC_LIB=n. So the code of driver/char/rtc is still useless.
>
> This breaks the API since there is no more misc device /dev/rtc
> available without a udev rule or a link to /dev/rtc0.


--
~Randy

2014-04-28 19:24:53

by John Stultz

[permalink] [raw]
Subject: Re: X86: Impossible select Enhanced Real Time Clock Support (legacy PC RTC driver)

On Mon, Apr 21, 2014 at 10:58 AM, Randy Dunlap <[email protected]> wrote:
> [adding more patch committers]
>
> On 04/13/2014 12:05 PM, Stefani Seibold wrote:
>> Since some kernel version it is impossible to select the Enhanced Real
>> Time Clock Support (legacy PC RTC driver) because RTC_LIB is set by
>> default in arch/x86/Kconfig, but the rule for selecting CONFIG_RTC is
>> RTC_LIB=n. So the code of driver/char/rtc is still useless.
>>
>> This breaks the API since there is no more misc device /dev/rtc
>> available without a udev rule or a link to /dev/rtc0.

So yea.. I feel like that /dev/rtcN renaming (and API) break (which
was a huge and annoying pain) was back in the 2.6.18-ish era?

But it sounds like the driver/char/rtc bit is dead code, and needs a
cleanup? Or is there some use of that code that you need that the
generic RTC layer doesn't have?

thanks
-john

2014-04-28 21:59:12

by Alessandro Zummo

[permalink] [raw]
Subject: Re: X86: Impossible select Enhanced Real Time Clock Support (legacy PC RTC driver)

On Mon, 28 Apr 2014 11:16:37 -0700
John Stultz <[email protected]> wrote:

> >> This breaks the API since there is no more misc device /dev/rtc
> >> available without a udev rule or a link to /dev/rtc0.
>
> So yea.. I feel like that /dev/rtcN renaming (and API) break (which
> was a huge and annoying pain) was back in the 2.6.18-ish era?

It's very old and linking/renaming is around since then.

> But it sounds like the driver/char/rtc bit is dead code, and needs a
> cleanup? Or is there some use of that code that you need that the
> generic RTC layer doesn't have?

as far as I know, no recent distribution is using the old code
anymore and the new (well, not so new anymore) framework provides the same functionality.


--

Best regards,

Alessandro Zummo,
Tower Technologies - Torino, Italy

http://www.towertech.it