[PATCHv2,3/3] mtd: onenand: implement cache program feature for 4kb page onenand

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/onenand_base.c |   22 +++++++++++++++++++---
 1 files changed, 19 insertions(+), 3 deletions(-)

Acked-by: Kyungmin Park <kyungmin.park@samsung.com>

On Wed, Nov 3, 2010 at 7:55 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/onenand_base.c |   22 +++++++++++++++++++---
>  1 files changed, 19 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c
> index 6b3a875..4d6e6c5 100644
> --- a/drivers/mtd/onenand/onenand_base.c
> +++ b/drivers/mtd/onenand/onenand_base.c
> @@ -1845,7 +1845,7 @@ 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 +1954,19 @@ 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;
> +               cmd = ONENAND_CMD_PROG;
> +
> +               /* Exclude 1st OTP and OTP blocks for cache program feature */
> +               if (ONENAND_IS_CACHE_PROGRAM(this) &&
> +                   likely(onenand_block(this, to) != 0) &&
> +                   ONENAND_IS_4KB_PAGE(this) &&
> +                   ((written + thislen) < len)) {
> +                       cmd = ONENAND_CMD_2X_CACHE_PROG;
> +                       this->ongoing = 1;
> +               }
> +
> +               this->command(mtd, cmd, to, mtd->writesize);
>
>                /*
>                 * 2 PLANE, MLC, and Flex-OneNAND wait here
> @@ -3377,8 +3389,10 @@ static void onenand_check_features(struct mtd_info *mtd)
>        case ONENAND_DEVICE_DENSITY_4Gb:
>                if (ONENAND_IS_DDP(this))
>                        this->options |= ONENAND_HAS_2PLANE;
> -               else if (numbufs == 1)
> +               else if (numbufs == 1) {
>                        this->options |= ONENAND_HAS_4KB_PAGE;
> +                       this->options |= ONENAND_HAS_CACHE_PROGRAM;
> +               }
>
>        case ONENAND_DEVICE_DENSITY_2Gb:
>                /* 2Gb DDP does not have 2 plane */
> @@ -3415,6 +3429,8 @@ 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");
>  }
>
>  /**
> --
> 1.7.0.4
>
>
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