Re: [PATCH] mtd: apply tPROG delay for ONFI nand's page program

[Huang Shijie]

ä 2013å01æ14æ 20:28, Matthieu CASTET åé:
> Huang Shijie a Ãcrit :
> > With some latest Micron's onfi nand(such as MT29F64G08CBABAWP),
> > I find that if we do not apply the tPROG delay as the datasheet tells us,
> > the page program may fails. You will read out the all 0xff from this page
> > in this case.
> >
> > This patch adds the tPROG delay for page program when it is an onfi nand.
> >
> > Signed-off-by: Huang Shijie<b32955@xxxxxxxxxxxxx>
> > ---
> >   drivers/mtd/nand/nand_base.c |    4 ++++
> >   1 files changed, 4 insertions(+), 0 deletions(-)
> >
> > diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
> > index 8323ac9..b628dd5 100644
> > --- a/drivers/mtd/nand/nand_base.c
> > +++ b/drivers/mtd/nand/nand_base.c
> > @@ -841,6 +841,10 @@ static int nand_wait(struct mtd_info *mtd, struct nand_chip *chip)
> >   	 */
> >   	ndelay(100);
> >
> > +	/* Apply the tPROG delay for ONFI nand program. */
> > +	if (chip->onfi_version&&  state == FL_WRITING)
> > +		udelay(le16_to_cpu(chip->onfi_params.t_prog));
> > +
> >   	if ((state == FL_ERASING)&&  (chip->options&  NAND_IS_AND))
> >   		chip->cmdfunc(mtd, NAND_CMD_STATUS_MULTI, -1, -1);
> >   	else
> It looks wrong : why should be wait tPROG before using status command to monitor
> program end ?
>
> tPROG is the Page program time (Measured from the falling edge of SR[6] to the
> rising edge of SR[6]), but because we monitor SR[6] with status command, we
> already wait for that time.
thanks. you are right. Please ignore this patch.
> Are you sure that it is not a bug in your nand driver with status command ?
I will try to find the bug in the driver.

thanks
Huang Shijie
> Matthieu


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/