Messages in this thread | | | Subject | Re: linux interrupt handling problem | Date | Tue, 9 Nov 1999 16:37:32 +0000 (GMT) | From | Alan Cox <> |
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> We already have this feature, you run the critical interrupt as > SA_INTERRUPT, the rest as normal sti() ones. The 7 priorities don't > buy you anything.
On a low end box with tight IRQ timing they buy you a lot. There are reasons MacOS does better than Linux on m68k serial performance. On modern machines and things like the PC what you say is very true but not on old m68k boxen
However there are much cleaner ways to attack this.
Add an arch specific
spin_lockat_cli(lock, flags, pri)
and make the normal cli() raise your IPL to screen all but what are effectively the 'real time' irqs. You don't want to do this in the generic driver case or for most platforms but used in the m68k serial drivers its pretty much essential - as on the mac it is for localtalk
Alan
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