Re[2]: [PATCH 06/12] mtd: nand: remove a bunch of unused commands

[Alexander Shiyan]

> On Mon, Mar 4, 2013 at 8:42 AM, Artem Bityutskiy <dedekind1 at gmail.com> wrote:
> > From: Artem Bityutskiy <artem.bityutskiy at linux.intel.com>
> >
> > Signed-off-by: Artem Bityutskiy <artem.bityutskiy at linux.intel.com>
> > ---
> >  drivers/mtd/nand/cafe_nand.c   |    6 ------
> >  drivers/mtd/nand/nand_base.c   |   10 ----------
> >  drivers/mtd/nand/nandsim.c     |    8 --------
> >  drivers/mtd/nand/nuc900_nand.c |    9 ---------
> >  include/linux/mtd/nand.h       |   20 --------------------
> >  5 files changed, 53 deletions(-)
> >
> 
> ... trimmed ...
...
> > - * Note: the command for NAND_CMD_DEPLETE1 is really 0x00 but
> > - *       there is no way to distinguish that from NAND_CMD_READ0
> > - *       until the remaining sequence of commands has been completed
> > - *       so add a high order bit and mask it off in the command.
> > - */
> > -#define NAND_CMD_DEPLETE1      0x100
> 
> Perhaps this is the reason for the "unnecessary command masking" noted
> by Alexander? There is one instance of a command function which masks
> command & 0xff. Maybe Alexander's patch can be updated to mention this
> likely cause for the original masking and can be applied on top of
> Artem's cleanup series? Anyway, the mask was likely not used anyway,
> since (as Artem mentions in this patch series) AG-AND had very little
> general use (or none?).

My patch is cleanup only. I think that the mask was originally included to
limit the byte boundaries. However, this is not necessary because callback
functions "cmd_ctrl" use writeb/iowrite8 for send command, ie do not allow
the use of the wrong size. Address also passed to "cmd_ctrl" via "cmd"
parameter, which is not masked but only shifted, i.e. we have a values
above 0xff, so that is not a problem.

---