Ubuntu
udev package

  1. Bug #252924
  2. Comment #15

Comment 15 for bug 252924

Revision history for this message
Scott James Remnant (Canonical) (canonical-scott) wrote : Re: [Bug 252924] Re: /dev/rtc symlink not pointing at /dev/rtcN

On Fri, 2008-10-24 at 06:10 +0000, Darik Horn wrote:

> A refinement of the proposed udev rule would be
>
> KERNEL=="rtc0", ATTR{name}=="rtc_cmos", DRIVERS=="rtc_cmos",
> SYMLINK+="rtc"
>
Actually, it need not be that complex:

  SUBSYSTEM=="rtc", DRIVERS=="rtc_cmos", SYMLINK+="rtc"

This would preserve the "CMOS RTC is /dev/rtc" behaviour from previous
kernels, any additional RTCs wouldn't be linked there - but unless I'm
misunderstanding this, the kernel never had a /dev/rtc for those before
anyway.

> so that it catches the corner-case of a customized local kernel with a
> second static rtc driver. A solution any more fancy would require
> something like writing a '70-persistent-rtc.rules' file and a patching
> `/lib/udev/path_id` to recognize the rtc device class.
>
After talking to upstream, I'm convinced that anything fancier should
enumerate RTC devices the "modern" way.

Preserving the /dev/rtc symlink for the CMOS driver is correct though.

Scott
--
Scott James Remnant
<email address hidden>