Hi Chris,
On Mon, Feb 14, 2011 at 11:40 AM, Chris Ball <cjb@xxxxxxxxxx> wrote:
> Hi Dmitry,
>
> [Cc += Nico]
>
> On Mon, Feb 14, 2011 at 11:04:13AM -0800, Dmitry Shmidt wrote:
>> MMC_UNSAFE_RESUME is affecting mmc_sdio_resume() sequence. If it is
>> not defined then sdio card will be considered
>> "removable" and on resume mmc_sdio_init_card() will be always called.
>>
>> static int mmc_sdio_resume(struct mmc_host *host)
>> {
>> ...
>> if (mmc_card_is_removable(host) || !mmc_card_is_powered_resumed(host))
>> err = mmc_sdio_init_card(host, host->ocr, host->card,
>> (host->pm_flags & MMC_PM_KEEP_POWER));
>
> mmc_sdio_init_card() is supposed to be called if your card is removable,
> because the card might have changed. It has a fast path that's enabled
> by MMC_PM_KEEP_POWER. (Nicolas explained this back in October.)
>
> You absolutely should not enable MMC_UNSAFE_RESUME if your host has a
> removable card. It's an awful hack, and you just found an example of
> where it breaks.
My main concern was that here we are mixing two things: removable
cards and cards that stay powered and need quick resume.
It is possible to assume that last ones are not removable, but I feel
it is not 100% correct. For example you may have
removable wlan sdio adaptor.
> If you need mmc_sdio_resume() to have an even faster path for you, we can
> talk about that and see if it makes sense. Misusing MMC_UNSAFE_RESUME to
> get a powered SDIO resume is just wrong.
So what can we do to suppress resume for removable sdio card ?
>
> Thanks,
>
> --
> Chris Ball <cjb@xxxxxxxxxx> <http://printf.net/>
> One Laptop Per Child
>
Thanks,
Dmitry
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