> On Tue, Oct 27, 2009 at 04:52:40PM -0600, Jonathan Haws wrote: > > > Will the device respond to 0x1234 being written at offset zero? > You > > > generally have to poke these things pretty specifically in order > to > > > get > > > them to go into command mode. > > > > > > > It should because that is the first data location in flash. > > I don't follow. Even if you have an Intel command set flash (and > thus don't > need unlock writes), 0x1234 isn't a valid command that I know of. > The flash > doesn't behave as a register that you can read back; it just > responds in a > certain way based on what you write to it. > > > Also, just to be sure I am telling the truth, I tried writing to > one of > > the registers to setup an erase and got the same results - the > value did > > not get written. > > Following the exact sequence that the driver uses? What did you > write, what > did you expect (you're generally not going to get the same thing > back that > you wrote), and what did you get? What kind of command set, bus > width, and > interleaving do you have?
I used the erase pattern, then write pattern for my flash device. When I tried to read back the value that should have been stored, it was what it was previously. > > If you manually do the same exact accesses from a firmware prompt, > external > debugger, etc. does it work? > > > > > The driver works perfectly in VxWorks, > > On this exact hardware? Yes. > > > Including the 0x1234 thing? > > > > Actually, I have not tried that - I have not had to since the > driver worked. > > What happens without the 0x1234? Have not bothered to try it. My guess, after finding out what the problem is that it would not read back 0x1234. In the test I performed, I intended to erase the sector, prep it for write, then write out 0x1234 to the first two bytes in flash. However, I failed in include the code to erase and prep the sector for writing in my rush to find out what the heck was going on. As I mentioned previously, I was just not allowing the correct sequence of operations to take place to erase the sector (that is where my problem began) because when I setup the sector for erasure, the sequencing did not take place correctly because what I would assign to flash was not committed immediately. I hope that makes sense. Thanks, Jonathan _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
