Re: [PATCH v2 5/8] MTD: xway: add missing write_buf and read_buf to nand driver

[Boris Brezillon <boris.brezillon@free-electrons.com>]

On Sat, 18 Jun 2016 21:14:09 +0200
Hauke Mehrtens <hauke@hauke-m.de> wrote:

Please add a commit message.

> From: John Crispin <john@phrozen.org>
> 
> Signed-off-by: John Crispin <john@phrozen.org>
> Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
> ---
>  drivers/mtd/nand/xway_nand.c | 29 +++++++++++++++++++++++++++++
>  1 file changed, 29 insertions(+)
> 
> diff --git a/drivers/mtd/nand/xway_nand.c b/drivers/mtd/nand/xway_nand.c
> index 61176c4..1511bdb 100644
> --- a/drivers/mtd/nand/xway_nand.c
> +++ b/drivers/mtd/nand/xway_nand.c
> @@ -151,6 +151,33 @@ static unsigned char xway_read_byte(struct mtd_info *mtd)
>  	return ret;
>  }
>  
> +
> +static void xway_read_buf(struct mtd_info *mtd, u_char *buf, int len)
> +{
> +	struct nand_chip *this = mtd_to_nand(mtd);
> +	unsigned long nandaddr = (unsigned long) this->IO_ADDR_R;
> +	unsigned long flags;
> +	int i;
> +
> +	spin_lock_irqsave(&ebu_lock, flags);
> +	for (i = 0; i < len; i++)
> +		buf[i] = ltq_r8((void __iomem *)(nandaddr | NAND_READ_DATA));

Please remove these useless cast and use the + operator.

		buf[i] = ltq_r8(this->IO_ADDR_R + NAND_READ_DATA);

> +	spin_unlock_irqrestore(&ebu_lock, flags);

Reading data through the NAND bus can be quite long, do you really need
to take a spinlock and disable irqs for while doing that?
A mutex would be more appropriate IMO.

> +}
> +
> +static void xway_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
> +{
> +	struct nand_chip *this = mtd_to_nand(mtd);
> +	unsigned long nandaddr = (unsigned long) this->IO_ADDR_W;
> +	unsigned long flags;
> +	int i;
> +
> +	spin_lock_irqsave(&ebu_lock, flags);
> +	for (i = 0; i < len; i++)
> +		ltq_w8(buf[i], (void __iomem *)(nandaddr | NAND_WRITE_DATA));

Ditto.

> +	spin_unlock_irqrestore(&ebu_lock, flags);
> +}
> +
>  /*
>   * Probe for the NAND device.
>   */
> @@ -184,6 +211,8 @@ static int xway_nand_probe(struct platform_device *pdev)
>  	data->chip.cmd_ctrl = xway_cmd_ctrl;
>  	data->chip.dev_ready = xway_dev_ready;
>  	data->chip.select_chip = xway_select_chip;
> +	data->chip.write_buf = xway_write_buf;
> +	data->chip.read_buf = xway_read_buf;
>  	data->chip.read_byte = xway_read_byte;
>  	data->chip.chip_delay = 30;
>