Re: [PATCH 3/4] MMC/core: Make sure the power is up, when detect the card

[Ulf Hansson <ulf.hansson@stericsson.com>]

Hi Jerry,

r66093@freescale.com wrote:
> From: Jerry Huang <Chang-Ming.Huang@freescale.com>
> 
> Before running get_cd() recall function to detect whether the card is
> present, must make sure the power is up.
> 
> Signed-off-by: Jerry Huang <Chang-Ming.Huang@freescale.com>
> ---
>  drivers/mmc/core/core.c |    2 ++
>  1 files changed, 2 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index 5278ffb..a08e6b1 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -2066,8 +2066,10 @@ void mmc_rescan(struct work_struct *work)
>  	 */
>  	mmc_bus_put(host);
>  
> +	mmc_power_up(host);
>  	if (host->ops->get_cd && host->ops->get_cd(host) == 0)
>  		goto out;
> +	mmc_power_off(host);

This does not feel right. get_cd is typically a function which makes use 
of some GPIO pin to find out if there is a card present and thus no 
power_up should be needed.

If your host driver does not support GPIO mechanism of detecting the 
card, the polling mechanism is maybe what you want.

>  
>  	mmc_claim_host(host);
>  	for (i = 0; i < ARRAY_SIZE(freqs); i++) {


Best regards
Ulf Hansson