[PATCH] mmc: dw_mmc: fix dw_mci_get_cd

[Seungwon Jeon]

On Wed, January 15, 2014, Zhangfei Gao wrote:
> Introduced from commit bf626e5550f24aec24975a0e85ad8e572ca76a6b
> CDETECT is ignored since negated return value of mmc_gpio_get_cd(mmc)
> can not be checked by IS_ERR_VALUE.
> Add spin_lock_bh(&host->lock) for atomic accessing DW_MMC_CARD_PRESENT,
> otherwise sd detect may occasionally fail.
> 
> Signed-off-by: Zhangfei Gao <zhangfei.gao at linaro.org>
> Reported-by: Kevin Hilman <khilman at linaro.org>
> Reviewed-by: Sachin Kamat <sachin.kamat at linaro.org>
> Tested-by: Sachin Kamat <sachin.kamat at linaro.org>
> ---
>  drivers/mmc/host/dw_mmc.c |    9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index a776f24f4311..9ded62c8225e 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -1033,7 +1033,8 @@ static int dw_mci_get_cd(struct mmc_host *mmc)
>  	int present;
>  	struct dw_mci_slot *slot = mmc_priv(mmc);
>  	struct dw_mci_board *brd = slot->host->pdata;
> -	int gpio_cd = !mmc_gpio_get_cd(mmc);
> +	struct dw_mci *host = slot->host;
> +	int gpio_cd = mmc_gpio_get_cd(mmc);
> 
>  	/* Use platform get_cd function, else try onboard card detect */
>  	if (brd->quirks & DW_MCI_QUIRK_BROKEN_CARD_DETECTION)
> @@ -1041,11 +1042,12 @@ static int dw_mci_get_cd(struct mmc_host *mmc)
>  	else if (brd->get_cd)
>  		present = !brd->get_cd(slot->id);
>  	else if (!IS_ERR_VALUE(gpio_cd))
> -		present = !!gpio_cd;
> +		present = !gpio_cd;
!!gpio_cd or gpio_cd is correct, isn't it?

Thanks,
Seungwon Jeon

>  	else
>  		present = (mci_readl(slot->host, CDETECT) & (1 << slot->id))
>  			== 0 ? 1 : 0;
> 
> +	spin_lock_bh(&host->lock);
>  	if (present) {
>  		set_bit(DW_MMC_CARD_PRESENT, &slot->flags);
>  		dev_dbg(&mmc->class_dev, "card is present\n");
> @@ -1053,6 +1055,7 @@ static int dw_mci_get_cd(struct mmc_host *mmc)
>  		clear_bit(DW_MMC_CARD_PRESENT, &slot->flags);
>  		dev_dbg(&mmc->class_dev, "card is not present\n");
>  	}
> +	spin_unlock_bh(&host->lock);
> 
>  	return present;
>  }
> @@ -2081,7 +2084,7 @@ static int dw_mci_of_get_wp_gpio(struct device *dev, u8 slot)
>  	return gpio;
>  }
> 
> -/* find the cd gpio for a given slot; or -1 if none specified */
> +/* find the cd gpio for a given slot */
>  static void dw_mci_of_get_cd_gpio(struct device *dev, u8 slot,
>  					struct mmc_host *mmc)
>  {
> --
> 1.7.9.5
> 
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