Accessing flash directly from User Space

Kenneth Johansson kenneth at
Wed Oct 28 20:56:45 EST 2009

On Tue, 2009-10-27 at 16:52 -0600, Jonathan Haws wrote:
> > Jonathan Haws wrote:
> > > I had thought about using MTD, but decided against it because with
> > > previous benchmarking that we did with MTD and our custom driver,
> > we
> > > found that our custom driver was about 10x faster.
> > 
> > Ouch.  Any idea where the slowdown is coming from?
> From what I remember (I would have to dig up notes to make sure) it is something to do with MTD looking for a signal to go high that is processed a bunch before MTD even sees it.  Our flash produces a hardware ready signal that we are triggering off of to move on.  MTD took much longer to report to us that the hardware was ready.
> Thanks

It would be interesting to know in more detail what is was. If we have a
10x performance increase hiding from for us I would be very interested
in knowing where it is.

Are you using some custom command to the flash that the generic chip
drivers in Linux is not yet supporting ?

More information about the Linuxppc-dev mailing list