Re: [PATCH V7 1/4] MTD: pxa3xx_nand: enhance suspend and resume routine

[Sergei Shtylyov <sshtylyov@mvista.com>]

Hello.

On 12-07-2011 18:35, Lei Wen wrote:

> This patch add protection on the suspend&resume path to prevent
> some unexpected behavior, like interrupt occur at the very second
> of resume back and it don't follow normal command path, which lead
> to bug.

> Signed-off-by: Lei Wen<leiwen@marvell.com>
> ---
>   drivers/mtd/nand/pxa3xx_nand.c |   17 ++++++++++++++++-
>   1 files changed, 16 insertions(+), 1 deletions(-)

> diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c
> index b7db1b2..1efecf7 100644
> --- a/drivers/mtd/nand/pxa3xx_nand.c
> +++ b/drivers/mtd/nand/pxa3xx_nand.c
> @@ -1158,23 +1158,38 @@ static int pxa3xx_nand_probe(struct platform_device *pdev)
>   static int pxa3xx_nand_suspend(struct platform_device *pdev, pm_message_t state)
>   {
>   	struct pxa3xx_nand_info *info = platform_get_drvdata(pdev);
> +	struct mtd_info *mtd;
>
>   	if (info->state) {
>   		dev_err(&pdev->dev, "driver busy, state = %d\n", info->state);
>   		return -EAGAIN;
>   	}
>
> +	mtd = info->mtd;

    Why not make this into an initializer?

> +	mtd->suspend(mtd);
>   	return 0;
>   }
>
>   static int pxa3xx_nand_resume(struct platform_device *pdev)
>   {
>   	struct pxa3xx_nand_info *info = platform_get_drvdata(pdev);
> +	struct mtd_info *mtd;
> +
> +	/* We don't want to handle interrupt without calling mtd routine */
> +	disable_int(info, NDCR_INT_MASK);
>
>   	nand_writel(info, NDTR0CS0, info->ndtr0cs0);
>   	nand_writel(info, NDTR1CS0, info->ndtr1cs0);
> -	clk_enable(info->clk);
>
> +	/*
> +	 * As the spec, the NDSR would be updated to 0x1800 when

    As the spec says?

> +	 * do the nand_clk disable/enable.

    Doing.

> +	 * To prevent it damage state machine of the driver, clear

    From damaging?

> +	 * all status before resume
> +	 */
> +	nand_writel(info, NDSR, NDSR_MASK);
> +	mtd = info->mtd;

    This one too could be an initializer...

> +	mtd->resume(mtd);
>   	return 0;
>   }
>   #else

WBR, Sergei