Hi Boris, > -----Original Message----- > From: Boris Brezillon <[email protected]> > Sent: Wednesday, June 26, 2019 4:57 PM > To: Naga Sureshkumar Relli <[email protected]> > Cc: [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; linux- > [email protected]; [email protected] > Subject: Re: [LINUX PATCH v17 1/2] mtd: rawnand: nand_micron: Do not over > write > driver's read_page()/write_page() > > On Wed, 26 Jun 2019 11:22:33 +0000 > Naga Sureshkumar Relli <[email protected]> wrote: > > > Hi Boris, > > > > > -----Original Message----- > > > From: Boris Brezillon <[email protected]> > > > Sent: Wednesday, June 26, 2019 12:18 PM > > > To: Naga Sureshkumar Relli <[email protected]> > > > Cc: [email protected]; [email protected]; > > > [email protected]; [email protected]; [email protected]; > > > [email protected]; [email protected]; [email protected]; > > > [email protected]; linux- [email protected]; > > > [email protected] > > > Subject: Re: [LINUX PATCH v17 1/2] mtd: rawnand: nand_micron: Do not > > > over write driver's read_page()/write_page() > > > > > > On Mon, 24 Jun 2019 22:46:29 -0600 > > > Naga Sureshkumar Relli <[email protected]> wrote: > > > > > > > Add check before assigning chip->ecc.read_page() and > > > > chip->ecc.write_page() > > > > > > > > Signed-off-by: Naga Sureshkumar Relli > > > > <[email protected]> > > > > --- > > > > drivers/mtd/nand/raw/nand_micron.c | 7 +++++-- > > > > 1 file changed, 5 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/drivers/mtd/nand/raw/nand_micron.c > > > > b/drivers/mtd/nand/raw/nand_micron.c > > > > index cbd4f09ac178..565f2696c747 100644 > > > > --- a/drivers/mtd/nand/raw/nand_micron.c > > > > +++ b/drivers/mtd/nand/raw/nand_micron.c > > > > @@ -500,8 +500,11 @@ static int micron_nand_init(struct nand_chip *chip) > > > > chip->ecc.size = 512; > > > > chip->ecc.strength = chip->base.eccreq.strength; > > > > chip->ecc.algo = NAND_ECC_BCH; > > > > - chip->ecc.read_page = micron_nand_read_page_on_die_ecc; > > > > - chip->ecc.write_page = > > > > micron_nand_write_page_on_die_ecc; > > > > + if (!chip->ecc.read_page) > > > > + chip->ecc.read_page = > > > > micron_nand_read_page_on_die_ecc; > > > > + > > > > + if (!chip->ecc.write_page) > > > > + chip->ecc.write_page = > > > > micron_nand_write_page_on_die_ecc; > > > > > > That's wrong, if you don't want on-die ECC to be used, simply don't > > > set nand-ecc-mode to "on- die". > > Ok. But if we want to use on-die ECC then you mean to say it is mandatory > > to use > micron_nand_read/write_page_on_die_ecc()? > > Absolutely, and if it doesn't work that means you driver does not > implement raw accesses correctly, which means it's still buggy... I agree. But let's say, if there is a limitation with the controller. Then it is must to have this check right? I mean, for pl353 controller, we must clear the CS during the data phase, hence we are splitting the Transfer in the pl353_read/write_page_raw(). + pl353_nand_read_data_op(chip, buf, mtd->writesize, false); + p = chip->oob_poi; + pl353_nand_read_data_op(chip, p, + (mtd->oobsize - + PL353_NAND_LAST_TRANSFER_LENGTH), false); + p += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH); + xnfc->dataphase_addrflags |= PL353_NAND_CLEAR_CS; + pl353_nand_read_data_op(chip, p, PL353_NAND_LAST_TRANSFER_LENGTH, + false); As the above sequence is needed even for raw access, PL353 is unable to use the on_die_page reads.
Thanks, Naga Sureshkumar Relli
