Messages in this thread | | | Date | Sat, 14 Aug 1999 16:28:44 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: New resources - pls, explain :-( |
| |
On Sat, 14 Aug 1999, Gerard Roudier wrote: > > > > where the "b800-b8ff" region is the actual PCI resource of the "NCR > > 53c895" controller, while the "b800-b87f" sub-region is the sym53c8xx > > driver that has marked that part of the resource busy (don't ask me why > > the driver only wants to look at the first 128 bytes of the 256 byte > > decode - I just show them as I see them). > > The SYM53C895 chip only implements 128 bytes of IO registers. The upper > 128 bytes of the IO window just map the same registers as the lower 128 > bytes. Without any concept of resource allocation, it did not seem this > usefull to care about more than 128 bytes of IO registers. Now, we > probably should want to care about the full 256 bytes IO window for this > chip.
No, that's fine. That's exactly the kind of explanation I would have expected, and I think it's actually _nice_ that /proc kind of shows both parts of the picture - no point in making the driver claim the whole window if it's only using half of it.
It's not as if the resource allocation protects against _bad_ users anyway: if somebody wants to mess with the IO registers he could just do so directly without bothering to try to allocate it as a busy resource. So there's no worry that some "bad" driver would try to access the card using the upper half - if somebody does something that silly on purpose, then it's not your problem, and you can't force him to behave by just marking the whole region used.
The PCI resource has been corectly identified, and as such there won't be anybody trying to allocate the area in question for any other bus.
Linus
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
| |