why can i select both PHYSMAP and MULTI_PHYSMAP?
Robert P. J. Day
rpjday at mindspring.com
Mon Apr 11 16:48:07 EDT 2005
On Mon, 11 Apr 2005, Josh Boyer wrote:
> On Mon, 2005-04-11 at 16:04 -0400, Robert P. J. Day wrote:
> > patched my 188.8.131.52 kernel tree with the latest mtd CVS to get the
> > mphysmap.c and i'm a bit confused. in the
> > Mapping drivers for chip access -->
> > menu, i can apparently select, simultaneously,
> > <*> CFI Flash device in physical memory map
> > <*> multiple CFI Flash devices in physical memory map
> > this seems contradictory, especially since i can deselect the first
> > while still select the second. am i misreading what these mean? or
> > is this some non-intuitive stuff to be backward-compatible?
> Joern (the author) is on vacation so I'll try to answer for him.
> I don't believe mphysmap precludes the use of physmap. They are
> entirely separate drivers and should be able to be used as such.
> For example, you could map one chip with physmap, and 3 others with
> That isn't the typical intended usage though. Normally you would
> use mphysmap to map all of the chips on a board. If you only had
> one chip, you could still use mphysmap. It's sort of
> backward-compatible that way I suppose.
i'd guessed as much -- it just seemed redundant to be able to use both
physmap and mphysmap at the same time, and possibly even refer to the
same chip in both places.
> If mphysmap proves to be useful and stable (it is fairly new), then
> maybe it can eventually replace physmap. Until then, I suppose it's
> safest to leave both there.
the one thing i don't see (perhaps i'm overlooking it) is the ability
to concatenate chips in menuconfig. perhaps that's getting overly
ambitious, but maybe it's not such a big step to throw in an option
for "Concatenate all chips in their numerical order?".
just thinking out loud.
More information about the linux-mtd