On Thu, Sep 15, 2016 at 05:05:29PM +0200, Boris Brezillon wrote: > MLC and TLC NAND devices are using NAND cells exposing more than one bit, > but instead of attaching all the bits in a given cell to a single NAND > page, each bit is usually attached to a different page. This concept is > called 'page pairing', and has significant impacts on the flash storage > usage. > The main problem showed by these devices is that interrupting a page > program operation may not only corrupt the page we are programming > but also the page it is paired with, hence the need to expose to MTD > users the pairing scheme information. > > The pairing APIs allows one to query pairing information attached to a > given page (here called wunit), or the other way around (the wunit > pointed by pairing information). > It also provides several helpers to help the conversion between absolute > offsets and wunits, and query the number of pairing groups. > > Signed-off-by: Boris Brezillon <boris.brezil...@free-electrons.com> > Reviewed-by: Brian Norris <computersforpe...@gmail.com> > --- > Hi Brian, > > Here is a new version addressing your comments. > If you're okay with this version, you can directly pull the > 4.9/mtd-pairing-scheme tag [1] into your tree (it's based on 4.8-rc1).
I never found where '[1]' was pointing, but I did pull 4.9/mtd-pairing-scheme from github.com:linux-nand/linux into linux-mtd.git. Thanks, Brian > Changes since v2: > - fix documentation > - make API consistent by returning error codes and adding bounds > checking everywhere > - drop NAND pairing scheme patches (will be resubmitted after > this patch has been merged) > > Changes since v1: > - document the paring scheme concepts and the associate structures and > helpers > - rework the dist3 and dist6 implementation according to George > comments > - introduce the mtd_set_pairing_scheme() helper to avoid directly > manipulating the mtd->pairing field > - drop the patch assigning dist6 pairing scheme to the H27UCG8T2ATR > NAND (in the light of George comment I'm not longer sure this scheme > is suitable for this NAND, and I can't test it) > > drivers/mtd/mtdcore.c | 104 ++++++++++++++++++++++++++++++++++++++++++++++ > drivers/mtd/mtdpart.c | 1 + > include/linux/mtd/mtd.h | 107 > ++++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 212 insertions(+)
