[PATCH] nand: Fix S3C NAND clock stop
Randy Dunlap
randy.dunlap at oracle.com
Sun Apr 10 22:05:14 EDT 2011
On 4/10/2011 6:27 PM, Jiri Pinkava wrote:
> Current implementation of s3c2410_nand_select_chip call
> clk_disable every time when chip = -1 (de-select). This happend
> multiple times even if chip was already de-selected. This causes
> disabling clock even if they are already disabled and due to
> nature of clock subsytem implementation this causes nand clock
> to be disabled and newer enabled again.
>
> Signed-off-by: Jiri Pinkava<jiri.pinkava at vscht.cz>
> ---
> drivers/mtd/nand/s3c2410.c | 57 +++++++++++++++++++++++++++++++------------
> 1 files changed, 41 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/mtd/nand/s3c2410.c b/drivers/mtd/nand/s3c2410.c
> index 33d832d..79e18a3 100644
> --- a/drivers/mtd/nand/s3c2410.c
> +++ b/drivers/mtd/nand/s3c2410.c
> @@ -159,11 +165,33 @@ static struct s3c2410_platform_nand *to_nand_plat(struct platform_device *dev)
> return dev->dev.platform_data;
> }
>
> -static inline int allow_clk_stop(struct s3c2410_nand_info *info)
> +static inline int allow_clk_suspend(struct s3c2410_nand_info *info)
> {
> return clock_stop;
> }
>
> +/**
> + * s3c2410_nand_clk_set_state - Enable, disable or suspend NAND clock.
> + * @info: The controller instance.
> + * @state: State to which clock should be set.
@new_state:
> + */
> +static void s3c2410_nand_clk_set_state(struct s3c2410_nand_info *info,
> + int new_state)
> +{
> + if (!allow_clk_suspend(info)&& new_state == CLOCK_SUSPEND)
> + return;
> +
> + if (clock_state == CLOCK_ENABLE) {
> + if (new_state != CLOCK_ENABLE)
> + clk_disable(info->clk);
> + } else {
> + if (new_state == CLOCK_ENABLE)
> + clk_enable(info->clk);
> + }
> +
> + clock_state = new_state;
> +}
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