Re: [PATCH 3/3] mtd/nand : workaround for Freescale FCM to supportlarge-page Nand chip

[LiuShuo]

ä 2011å12æ07æ 08:09, Scott Wood åé:
> On 12/03/2011 10:31 PM, shuo.liu@xxxxxxxxxxxxx wrote:
> > From: Liu Shuo<shuo.liu@xxxxxxxxxxxxx>
> >
> > Freescale FCM controller has a 2K size limitation of buffer RAM. In order
> > to support the Nand flash chip whose page size is larger than 2K bytes,
> > we read/write 2k data repeatedly by issuing FIR_OP_RB/FIR_OP_WB and save
> > them to a large buffer.
> >
> > Signed-off-by: Liu Shuo<shuo.liu@xxxxxxxxxxxxx>
> > ---
> > v3:
> >      -remove page_size of struct fsl_elbc_mtd.
> >      -do a oob write by NAND_CMD_RNDIN.
> >
> >   drivers/mtd/nand/fsl_elbc_nand.c |  243 ++++++++++++++++++++++++++++++++++----
> >   1 files changed, 218 insertions(+), 25 deletions(-)
> What is the plan for bad block marker migration?
This patch has been ported to uboot now, I think we can make a special 
uboot image for bad
block marker migration when first use the chip.

> > @@ -473,13 +568,72 @@ static void fsl_elbc_cmdfunc(struct mtd_info *mtd, unsigned int command,
> >   		 * write so the HW generates the ECC.
> >   		 */
> >   		if (elbc_fcm_ctrl->oob || elbc_fcm_ctrl->column != 0 ||
> > -		    elbc_fcm_ctrl->index != mtd->writesize + mtd->oobsize)
> > -			out_be32(&lbc->fbcr,
> > -				elbc_fcm_ctrl->index - elbc_fcm_ctrl->column);
> > -		else
> > +		    elbc_fcm_ctrl->index != mtd->writesize + mtd->oobsize) {
> > +			if (elbc_fcm_ctrl->oob&&  mtd->writesize>  2048) {
> > +				out_be32(&lbc->fbcr, 64);
> > +			} else {
> > +				out_be32(&lbc->fbcr, elbc_fcm_ctrl->index
> > +						- elbc_fcm_ctrl->column);
> > +			}
> We need to limit ourselves to the regions that have actually been
> written to in the buffer.  fbcr needs to be set separately for first and
> last subpages, with intermediate subpages having 0, 64, or 2112 as
> appropriate.  Subpages that are entirely before column or entirely after
> column + index should be skipped.

I have considered this case, but I don't think it is useful.
    1.There isn't a 'length' parameter in driver interface, although we 
can get it from 'index - column'.
    2.To see nand_do_write_oob() in nand_base.c, it fill '0xff' to 
entire oob area first and write the user data by nand_fill_oob(), then 
call ecc.write_oob (default is nand_write_oob_std()). 'column' is 
mtd->writesize and 'length' of write_buf() is mtd->oobsize. So I don't 
think we need to deal with it there.

> > +		} else {
> > +			out_be32(&lbc->fir, FIR_OP_WB<<  FIR_OP1_SHIFT);
> > +			for (i = 1; i<  n; i++) {
> > +				if (i == n - 1) {
> > +					elbc_fcm_ctrl->use_mdr = 1;
> > +					out_be32(&lbc->fir,
> > +						(FIR_OP_WB<<  FIR_OP1_SHIFT) |
> > +						(FIR_OP_CM3<<  FIR_OP2_SHIFT) |
> > +						(FIR_OP_CW1<<  FIR_OP3_SHIFT) |
> > +						(FIR_OP_RS<<  FIR_OP4_SHIFT));
> Please explicitly show the (FIR_OP_NOP<<  FIR_OP0_SHIFT) compenent.
>
> > +	} else if (mtd->writesize>= 2048&&  mtd->writesize<= 16 * 1024) {
> > +
> >   		setbits32(&lbc->bank[priv->bank].or, OR_FCM_PGS);
> Don't insert a blank line here.
Ok.

-LiuShuo
> -Scott


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