Re: [PATCH 06/15] mtd: rawnand: Add nand_[de]select_target() helpers

Miquel Raynal
2018-10-29T14:25:32Z

Boris Brezillon <boris.brezillon@bootlin.com> wrote on Mon, 29 Oct 2018
15:16:34 +0100:

> On Mon, 29 Oct 2018 15:06:41 +0100
> Miquel Raynal <miquel.raynal@bootlin.com> wrote:
>
> > Boris Brezillon <boris.brezillon@bootlin.com> wrote on Mon, 29 Oct 2018
> > 14:57:27 +0100:
> >
> > > On Mon, 29 Oct 2018 14:39:24 +0100
> > > Miquel Raynal <miquel.raynal@bootlin.com> wrote:
> > >
> > > > Miquel Raynal <miquel.raynal@bootlin.com> wrote on Mon, 29 Oct 2018
> > > > 14:36:47 +0100:
> > > >
> > > > > Hi Boris,
> > > > >
> > > > > Boris Brezillon <boris.brezillon@bootlin.com> wrote on Tue, 23 Oct 2018
> > > > > 20:50:02 +0200:
> > > > >
> > > > > > Add a wrapper to prevent drivers and core code from directly calling
> > > > > > the ->select_chip hook which we are about to deprecate.
> > > > > >
> > > > > > Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
> > > > > > ---
> > > > > > drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c | 23 +++--
> > > > > > drivers/mtd/nand/raw/jz4740_nand.c | 4 +-
> > > > > > drivers/mtd/nand/raw/nand_base.c | 114 ++++++++++++++-------
> > > > > > drivers/mtd/nand/raw/r852.c | 4 +-
> > > > > > include/linux/mtd/rawnand.h | 4 +
> > > > > > 5 files changed, 98 insertions(+), 51 deletions(-)
> > > > > >
> > > > >
> > > > > So far I am glad to see all these changes.
> > > > >
> > > > > About the ->select_chip() removal, I wonder if it would not be better
> > > > > to also change the local variables "chipnr" or "chip_number" (or
> > > > > even "i") that suggest that this ID selects a chip, while it
> > > > > actually selects a die in a chip (and it is possible to have multiple
> > > > > die on a chip, so multiple CS for one single NAND chip).
> > >
> > > I agree.
> > >
> > > > >
> > > > > Do you think it is worth the change ? If yes, would it fit in this patch
> > > > > or is it better to do this change elsewhere?
> > > > >
> > > >
> > > > This request actually applies to the following patches as well. Maybe we
> > > > could even find a uniform way to name it, "die_nr" or something like
> > > > this?
> > >
> > > Target is the name used in the ONFI spec, hence the function names.
> > > Note that die is not accurate since you might have several dies exposed
> > > through a single CS line (that's called LUNs).
> >
> > I'm completely fine with the rename of the functions being now
> > <nfc>_select_target().
> >
> > What about renaming local variables -when relevant- as lun_nr? lun?
> > lun_idx?
>
> Nope, a LUN is a logically selection-able die, while a target is a
> physically selection-able one. We should rename the vars/args target or
> cs, not lun.

Ok then, let's try 'target' to avoid the confusion with

cs -> chip select -> NAND chip select

>
> >
> > Do you think it should be done in place in these patches or as a
> > separate change?
>
> I think it should be done separately.

Ok.