[linux-pm] sleepy linux self-test

Ingo Molnar mingo at elte.hu
Sat Feb 2 10:06:04 PST 2008


* David Brownell <david-b at pacbell.net> wrote:

> On Saturday 02 February 2008, Ingo Molnar wrote:
> > 
> > i'd really love to have a /dev/rtc device compatibility APIs, both 
> > inside and outside the kernel.
> 
> Unfortunately the /dev/rtc code became a legacy API for good reasons.
> 
> Like not recognizing that all the world's not a PC, with a single RTC 
> that clones a long-obsolete chip from Motorola ... and not having been 
> specified in a hardware-neutral manner.  Oh, and of course not all 
> systems actually used the same RTC driver anyway; it's not like there 
> was just *one* such programming interface to worry about.

i dont get it - please give me specific technological reasons why on my 
PC /dev/rtc couldnt be mapped to /dev/rtc0 - without requiring any 
user-space changes. The APIs seem mostly covered, or at least mappable. 
Why should the transition to a new driver require user-level changes? 
(beyond the obvious extensions, but those should show up as extensions.) 

In fact i detest the old RTC code with a vengence, so dont understand 
this as some invitation to flame or something - i simply want YOUR new 
code to be utilized more! I just dont see the specific technological 
reasons of why there is no .config switch to switch the legacy /dev/rtc 
over to the new RTC driver and be done with it. I'd enable it in a 
heartbeat and would encourage distros to do so. Are there missing APIs? 
Is the ioctl API totally different? It's impossible to wrap it? I'm not 
really interested in "this isnt a PC" arguments. The incompatibility is 
such an obvious migration barrier to me - do you really not see it?

	Ingo


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