John Dennis writes: > > Now it seems to me that using extra machine instructions (asm version) > or no-op IO is inherently a risky solution to this problem. It would > appear there is some interval of time one must wait for individual VGA > bus transactions complete. The number of extra machine instructions > and/or no-op IO to insert seems to be purely a guess and highly > dependent on the processor and the bus its sitting on. The fact this > works on one class of machines and not another does not surprise me at > all. >
No, I've tried this already. The out() on port 0x80 did some flushing appearantly which made things work. Note that I arrived at this solution purely by guessing. There may be a better fix for that. > > 3) Can we come up with a scheme that introduces a known timing delay > (e.g. usleep) such that we don't have to make arbitrary guesses as to > how much no-op is needed in the loop on a given system? > I don't think so. See above. Egbert. _______________________________________________ Devel mailing list [EMAIL PROTECTED] http://XFree86.Org/mailman/listinfo/devel
