Hi,
On Tue, Feb 15, 2011 at 10:06 AM, Dmitry Shmidt <dimitrysh@xxxxxxxxxxx> wrote:
> Hi,
>
> [Cc += Ohad]
> On Mon, Feb 14, 2011 at 1:54 PM, Dmitry Shmidt <dimitrysh@xxxxxxxxxxx> wrote:
>> 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
>>>
> As I wrote, Ohad's patch resolves quick resume situation for
> non-removable cards, but in case of
> removable - it is not working.
>
> Thanks,
>
> Dmitry
>
As another point of inconsistency, the flag that is set by
MMC_UNSAFE_RESUME is global,
meaning that when set to 0, it makes all cards non-removable,
regardless of caps property.
Thanks,
Dmitry
--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
