[PATCH 4/4] Revert "mtd: atmel_nand: optimize read/write buffer functions"

[Jean-Christophe PLAGNIOL-VILLARD]

On 16:11 Sun 25 Nov     , 张忠山 wrote:
> > >
> > > This patch resolves my problem
> > I'm expecting to see your patches
> >
> 
> My first patch very simple:
your board patch

I'll be at the electronic market in SH tomorrow

Best Regards,
J.
> 
> ------------------
> diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
> index 0477178..a111463 100644
> --- a/drivers/mtd/nand/atmel_nand.c
> +++ b/drivers/mtd/nand/atmel_nand.c
> @@ -155,23 +155,6 @@ static int atmel_nand_device_ready(struct mtd_info *mtd)
>  }
> 
>  /*
> - * Minimal-overhead PIO for data access.
> - */
> -static void atmel_read_buf(struct mtd_info *mtd, u8 *buf, int len)
> -{
> -       struct nand_chip *chip = mtd->priv;
> -
> -       memcpy_fromio(buf, chip->IO_ADDR_R, len);
> -}
> -
> -static void atmel_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
> -{
> -       struct nand_chip *chip = mtd->priv;
> -
> -       memcpy_toio(chip->IO_ADDR_W, buf, len);
> -}
> -
> -/*
>   * Return number of ecc bytes per sector according to sector size and
>   * correction capability
>   *
> @@ -1115,8 +1098,9 @@ static int __init atmel_nand_probe(struct device_d *dev)
>         if (host->board->bus_width_16)          /* 16-bit bus width */
>                 nand_chip->options |= NAND_BUSWIDTH_16;
> 
> -       nand_chip->read_buf = atmel_read_buf;
> -       nand_chip->write_buf = atmel_write_buf;
> +       /* use default */
> +       nand_chip->read_buf = NULL;
> +       nand_chip->write_buf = NULL;
> 
>         atmel_nand_enable(host);
> ------------------
> 
> After seeing your patch, I suppose the flowing patch may be works.
> The idea is use optimized read/write function when 2**ale >= pagesize
> and 2**cle >= pagesize.
> 
> I can't test it because the ale = a7, cle = a6 on my board, but
> pagesize is 2048
> 
> ------------------
> diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
> index 0477178..66cf5db 100644
> --- a/drivers/mtd/nand/atmel_nand.c
> +++ b/drivers/mtd/nand/atmel_nand.c
> @@ -1115,8 +1115,8 @@ static int __init atmel_nand_probe(struct device_d *dev)
>         if (host->board->bus_width_16)          /* 16-bit bus width */
>                 nand_chip->options |= NAND_BUSWIDTH_16;
> 
> -       nand_chip->read_buf = atmel_read_buf;
> -       nand_chip->write_buf = atmel_write_buf;
> +       nand_chip->read_buf = NULL;
> +       nand_chip->write_buf = NULL;
> 
>         atmel_nand_enable(host);
> 
> @@ -1151,6 +1151,11 @@ static int __init atmel_nand_probe(struct device_d *dev)
>                         goto err_hw_ecc;
>         }
> 
> +       if((1 << pdata->ale) >= mtd->writesize && (1 << pdata->cle) >= mtd->writesize) {
> +               nand_chip->read_buf = atmel_read_buf;
> +               nand_chip->write_buf = atmel_write_buf;
> +       }
> +
>         /* second phase scan */
>         if (nand_scan_tail(mtd)) {
>                 res = -ENXIO;
> ------------------
> 
> -- 
> Best Regards,
> zzs
> 
>