Re: [PATCH] mtd: rawnand: Add Macronix NAND read retry and randomizer support

From: Boris Brezillon
Date: Tue Apr 09 2019 - 05:47:08 EST


On Tue, 9 Apr 2019 17:35:39 +0800
masonccyang@xxxxxxxxxxx wrote:

> > > +
> > > +static const struct kobj_attribute sysfs_mxic_nand =
> > > + __ATTR(nand_random, S_IRUGO | S_IWUSR,
> > > + mxic_nand_rand_type_show,
> > > + mxic_nand_rand_type_store);
> >
> > No, we don't want to expose that through a sysfs file, especially since
> > changing the randomizer config means making the NAND unreadable for
> > those that have used it before the change.
> >
>
> Our on-die randomizer is still readable from user after the function
> is enabled.

You mean the memory is still readable no matter the randomizer state.
Not sure how that's possible, but okay.

> This randomizer is just like a internal memory cell
> reliability enhanced.

Why don't you enable it by default then?

> It could be enable at any time with OTP bit function and that's why
> we patch it by sys-fs.

Sorry, but that's not a good reason to expose that through sysfs.