On Tue, Apr 20, 2004 at 03:41:32PM +0200, Maciej W. Rozycki wrote: > On Mon, 19 Apr 2004, Jun Sun wrote: > > > Solution > > -------- > > > > All the boards that I am really concerned right now have cpu count/compare > > registers. I believe this will even more so in the future. > > > > Therefore I like to propose a separate time support for systems that use > > cpu timer as their system timer. > > > > As you can see from the patch, the new code is much simpler. > > It makes it separate again -- more maintenance burden and a bigger > opportunity to have functional divergence, sigh... > Pretty much true for lots of improvement we made in the past a couple of years .... :) > Additionally I don't think using the CP0 Count & Compare registers for > the system timer is the way to go. It's rather a way to escape when > there's no other possibility. A lot of systems have a reliable external > timer interrupt source and using it actually would free the CP0 registers > for other uses, like profiling or a programmable interval timer. > I was rather neutral on this point until I started to add HRT/VST support to MIPS. When adding such features you really just want one common timer code. And the best choice for MIPS is cpu timer. BTW, I plan to submit MIPS/HRT support based on the cpu-timer patch. Hopefully this will catch more attention to the cpu timer patch.... Jun
