[LAU] RTC/HPET timer permissions

Brent Busby brent at keycorner.org
Mon Nov 26 15:24:29 UTC 2012


On Mon, 26 Nov 2012, Clemens Ladisch wrote:

> Jeremy Jongepier wrote:
>> On 11/25/2012 01:23 PM, Clemens Ladisch wrote:
>>> Using the RTC or HPET devices directly is necessary only if
>>> the kernel does not use them for timers.  Nowadays, kernels do, and
>>> applications use the proper timer APIs.
>>
>> What are those timer API's?
>
> POSIX timers, interval timers, nanosleep(), usleep(), poll() timeout.
>
>>> You'd need this only if you're using some audio application that hasn't
>>> been updated for many years.
>>
>> So this section has become deprecated?
>> http://wiki.linuxmusicians.com/doku.php?id=system_configuration#hardware_timers
>
> Only if all applications actually have been updated.
> Wasn't there some sequencer (Rosegarden? Muse?) that still uses RTC?

Can you imagine any reason why an app using /dev/rtc or /dev/hpet would 
need write access, or would it be sufficient to do something like 0640 
root:realtime ?

-- 
+ Brent A. Busby	 + "We've all heard that a million monkeys
+ Sr. UNIX Systems Admin +  banging on a million typewriters will
+ University of Chicago	 +  eventually reproduce the entire works of
+ James Franck Institute +  Shakespeare.  Now, thanks to the Internet,
+ Materials Research Ctr +  we know this is not true." -Robert Wilensky


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