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SubjectRe: [PATCH 1/2] mmc: core: Add a capability for disabling mmc cards
Hi Doug,

I didn't know what purpose is.
Why need to add the MMC_CAP2_NO_MMC?
If card is SD or SDIO, mmc_attach_mmc(host) should not be entered.
Could you explain to me in more detail?

Best Regards,
Jaehoon Chung

On 08/22/2012 01:05 PM, Doug Anderson wrote:
> On some systems we need a way to disable MMC card support in a MMC/SD
> card slot. Add support in the core SD/MMC code to support this.
>
> Signed-off-by: Doug Anderson <dianders@chromium.org>
> Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
> ---
> drivers/mmc/core/core.c | 2 +-
> include/linux/mmc/host.h | 1 +
> 2 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index 8ac5246..3214972 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -1981,7 +1981,7 @@ static int mmc_rescan_try_freq(struct mmc_host *host, unsigned freq)
> return 0;
> if (!mmc_attach_sd(host))
> return 0;
> - if (!mmc_attach_mmc(host))
> + if (!(host->caps2 & MMC_CAP2_NO_MMC) && !mmc_attach_mmc(host))
> return 0;
>
> mmc_power_off(host);
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index f578a71..f36370e 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -257,6 +257,7 @@ struct mmc_host {
> #define MMC_CAP2_HC_ERASE_SZ (1 << 9) /* High-capacity erase size */
> #define MMC_CAP2_CD_ACTIVE_HIGH (1 << 10) /* Card-detect signal active high */
> #define MMC_CAP2_RO_ACTIVE_HIGH (1 << 11) /* Write-protect signal active high */
> +#define MMC_CAP2_NO_MMC (1 << 12) /* Only SD supported, not MMC */
>
> mmc_pm_flag_t pm_caps; /* supported pm features */
> unsigned int power_notify_type;
>



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