[RFC][patch] NAND partial page read functionality

Jörn Engel joern at logfs.org
Tue Dec 18 08:51:03 EST 2007


On Tue, 18 December 2007 14:57:55 +0200, Artem Bityutskiy wrote:
> On Tue, 2007-12-18 at 12:42 +0100, Jörn Engel wrote:
> > On Tue, 18 December 2007 10:48:51 +0200, Artem Bityutskiy wrote:
> > > 
> > > Well, this depends. If an MTD user wants to write 4KiB, and issues 4KiB
> > > write request, then it is of course faster to write 2x2048, then 8x512,
> > > and it is even faster to do some kind of multi-page write (some old
> > > flashes had this AFAIK).
> > 
> > Not necessarily.  The alauda chip has a "page program" and a "block
> > program" command.  With a naive implementation the block program is
> > faster.  But when doing asynchronous transfers on the usb bus, page
> > program becomes just as fast.  In this particular case, block program
> > can only reduce the number of synchronous bus latencies for a
> > non-optimized implementation.
> 
> Well, in the context of discussion this example is not really relevant,
> since aluda have its own write_page, and we are talking about the
> nand_base.c's implementation.

Your claim above seemed to imply that larger transfers always improve
speed.  That simply isn't true.  If I misinterpreted your claim then
sorry about the noise.

Jörn

-- 
Chance favors only the prepared mind.
-- Louis Pasteur



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