Messages in this thread | | | Subject | Re: New resources - pls, explain :-( | From | Jes Sorensen <> | Date | 13 Aug 1999 14:15:41 +0200 |
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>>>>> "Paul" == Paul Mackerras <paulus@cs.anu.edu.au> writes:
Paul> Linus Torvalds <torvalds@transmeta.com> wrote: >> readl() is for things that want to look like PCI (ie subsets of PCI >> like ISA and ISA PnP, or "look-alikes" of PCI like MCA).
Paul> OK, that's indeed useful to know, thanks.
Paul> In your opinion, should there be a guarantee that accesses Paul> initiated by readl/writel/etc. will not be reordered?
Paul> Alternatively, should device driver writers be required to put Paul> in an explicit statement (mb() or something similar) when they Paul> use readl/writel/etc. and want to prevent the accesses being Paul> reordered?
Now that you bring this up here it might be a good idea to mention that we (you and I both included) have just been discussing this in a different forum and there is disagreement between the Alpha and PPC camps on this one.
My point is that the current implementation expects no protection against reordering and many current device drivers already deal with this correctly (I checked the aic7xxx this this morning and I noticed that it deals with this explicitly, even on the PPC).
Jes
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