Re: [Query] mmc: core "MMC_PM_KEEP_POWER"

[Chris Ball <cjb@laptop.org>]

Hi Ulf,

On Tue, Nov 22 2011, Ulf Hansson wrote:
> Thanks for the quick reply! I understand the idea better now. Just a
> minor follow-up question..
>
> The power_restore function for sdio also uses this flag, which is a
> little bit strange I think.

Yeah, it's being used to detect whether we're in the middle of a powered
resume, and therefore shouldn't be trying to reinit the card.  Then the
value of MMC_PM_KEEP_POWER gets reset once the resume's finished.

> Especially since the mmc_power_off|up is always called no matter of
> the value of this flag.

Hm, I don't think that's true.

mmc_suspend_host() checks !mmc_card_keep_power(host) before mmc_power_off()
mmc_resume_host() checks !mmc_card_keep_power(host) before mmc_power_up()

static inline int mmc_card_keep_power(struct mmc_host *host)
{
        return host->pm_flags & MMC_PM_KEEP_POWER;
}

Thanks,

- Chris.
-- 
Chris Ball   <cjb@laptop.org>   <http://printf.net/>
One Laptop Per Child