Re: [PATCH 3/3] mtd: onenand: implement cache program feature for 4kb page onenand

[Roman Tereshonkov <roman.tereshonkov@nokia.com>]

On Tue, Nov 02, 2010 at 03:00:41PM +0100, ext Kyungmin Park wrote:
> Hi,
> 
> On Tue, Nov 2, 2010 at 8:25 PM, Roman Tereshonkov
> <roman.tereshonkov@nokia.com> wrote:
> > Implement cache program feature for 4KB page onenand.
> > This feature improves the write data performance.
> > The observed 128KB data program speed change is
> > from 8827KB/s to 14156 KB/s when the feature is enabled.
> >
> > Signed-off-by: Roman Tereshonkov <roman.tereshonkov@nokia.com>
> > ---
> >  drivers/mtd/onenand/omap2.c        |   12 ++++++++--
> >  drivers/mtd/onenand/onenand_base.c |   39 ++++++++++++++++++++++++++++++++++-
> >  2 files changed, 46 insertions(+), 5 deletions(-)
> 
> Please make separate the two patches, one for OMAP, another is for
> onenand_base.c
> 
> >
> > diff --git a/drivers/mtd/onenand/omap2.c b/drivers/mtd/onenand/omap2.c
> > index 9f322f1..da25a90 100644
> > --- a/drivers/mtd/onenand/omap2.c
> > +++ b/drivers/mtd/onenand/omap2.c
> > @@ -108,8 +108,9 @@ static void wait_warn(char *msg, int state, unsigned int ctrl,
> >  static int omap2_onenand_wait(struct mtd_info *mtd, int state)
> >  {
> >        struct omap2_onenand *c = container_of(mtd, struct omap2_onenand, mtd);
> > +       struct onenand_chip *this = mtd->priv;
> >        unsigned int intr = 0;
> > -       unsigned int ctrl;
> > +       unsigned int ctrl, ctrl_mask;
> >        unsigned long timeout;
> >        u32 syscfg;
> >
> > @@ -180,7 +181,8 @@ retry:
> >                        if (result == 0) {
> >                                /* Timeout after 20ms */
> >                                ctrl = read_reg(c, ONENAND_REG_CTRL_STATUS);
> > -                               if (ctrl & ONENAND_CTRL_ONGO) {
> > +                               if (ctrl & ONENAND_CTRL_ONGO &&
> > +                                   !this->ongoing) {
> >                                        /*
> >                                         * The operation seems to be still going
> >                                         * so give it some more time.
> > @@ -269,7 +271,11 @@ retry:
> >                return -EIO;
> >        }
> >
> > -       if (ctrl & 0xFE9F)
> > +       ctrl_mask = 0xFE9F;
> > +       if (this->ongoing)
> > +               ctrl_mask &= ~0x8000;
> > +
> > +       if (ctrl & ctrl_mask)
> >                wait_warn("unexpected controller status", state, ctrl, intr);
> >
> >        return 0;
> > diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c
> > index 6b3a875..b2c3e97 100644
> > --- a/drivers/mtd/onenand/onenand_base.c
> > +++ b/drivers/mtd/onenand/onenand_base.c
> > @@ -440,6 +440,19 @@ static int onenand_command(struct mtd_info *mtd, int cmd, loff_t addr, size_t le
> >                default:
> >                        if (ONENAND_IS_2PLANE(this) && cmd == ONENAND_CMD_PROG)
> >                                cmd = ONENAND_CMD_2X_PROG;
> > +
> > +                       /* Exclude 1st OTP and OTP blocks */
> Are there any reason? I think 1st OTP block is just block 0 so no need
> to consider block 0 case.


Specification tells:
3.9.1 Cache Program Operation
"Note that Cache Program command cannot be performed on OTP block and 1st block OTP"


> > +                       if (ONENAND_IS_CACHE_PROGRAM(this) &&
> > +                           likely(onenand_block(this, addr) != 0) &&
> > +                           ONENAND_IS_4KB_PAGE(this)) {
> and I think no need to check 4KB_PAGE.


This patch is for 4kb page onenand only. The 2kb page onenand uses different
commands for cache program. Also 2kb page case cache program depends on
CONFIG_MTD_ONENAND_2X_PROGRAM.


> > +
> > +                               if (cmd == ONENAND_CMD_CACHE_PROG)
> > +                                       cmd = ONENAND_CMD_2X_CACHE_PROG;
> > +                               else if (cmd == ONENAND_CMD_CACHE_PROG_LAST)
> > +                                       cmd = ONENAND_CMD_PROG;
> > +
> > +                       }
> > +
> >                        dataram = ONENAND_CURRENT_BUFFERRAM(this);
> >                        break;
> >                }
> > @@ -1845,7 +1858,7 @@ static int onenand_write_ops_nolock(struct mtd_info *mtd, loff_t to,
> >        const u_char *buf = ops->datbuf;
> >        const u_char *oob = ops->oobbuf;
> >        u_char *oobbuf;
> > -       int ret = 0;
> > +       int ret = 0, cmd;
> >
> >        DEBUG(MTD_DEBUG_LEVEL3, "%s: to = 0x%08x, len = %i\n",
> >                __func__, (unsigned int) to, (int) len);
> > @@ -1954,7 +1967,25 @@ static int onenand_write_ops_nolock(struct mtd_info *mtd, loff_t to,
> >                        ONENAND_SET_NEXT_BUFFERRAM(this);
> >                }
> >
> > -               this->command(mtd, ONENAND_CMD_PROG, to, mtd->writesize);
> > +               this->ongoing = 0;
> > +
> > +               /* Exclude 1st OTP and OTP blocks */
> > +               if (ONENAND_IS_CACHE_PROGRAM(this) &&
> > +                   likely(onenand_block(this, to) != 0) &&
> > +                   ONENAND_IS_4KB_PAGE(this)) {
> check the length here instead of 4KB_PAGE.


This patch is for 4kb page onenand only. The 2kb page onenand uses different
commands for cache program.


> > +
> > +                       if ((written + thislen) < len) {
> > +                               cmd = ONENAND_CMD_CACHE_PROG;
> > +                               this->ongoing = 1;
> > +                       } else {
> > +                               cmd = ONENAND_CMD_CACHE_PROG_LAST;
> > +                       }
> Need to check how to pass the cmd properly. How/When send the CACHE_PROG_LAST?


CACHE_PROG_LAST command must be sent for last programmed piece of data, that is
(written + thislen) >= len.


> > +
> > +               } else {
> > +                       cmd = ONENAND_CMD_PROG;
> > +               }
> > +
> > +               this->command(mtd, cmd, to, mtd->writesize);
> >
> >                /*
> >                 * 2 PLANE, MLC, and Flex-OneNAND wait here
> > @@ -3380,6 +3411,8 @@ static void onenand_check_features(struct mtd_info *mtd)
> >                else if (numbufs == 1)
> >                        this->options |= ONENAND_HAS_4KB_PAGE;
> >
> > +               this->options |= ONENAND_HAS_CACHE_PROGRAM;
> It also needs to set CACHE_PROGRAM option.


Sorry. What do mean here?


> > +
> >        case ONENAND_DEVICE_DENSITY_2Gb:
> >                /* 2Gb DDP does not have 2 plane */
> >                if (!ONENAND_IS_DDP(this))
> > @@ -3415,6 +3448,8 @@ static void onenand_check_features(struct mtd_info *mtd)
> >                printk(KERN_DEBUG "Chip has 2 plane\n");
> >        if (this->options & ONENAND_HAS_4KB_PAGE)
> >                printk(KERN_DEBUG "Chip has 4KiB pagesize\n");
> > +       if (this->options & ONENAND_HAS_CACHE_PROGRAM)
> > +               printk(KERN_DEBUG "Chip has cache program feature\n");
> >  }
> 
> Thank you,
> Kyungmin Park