On 31/01/12 14:54, Ulf Hansson wrote:
> Adrian Hunter wrote:
>> On 19/01/12 18:39, Ulf Hansson wrote:
>>> Once the card has been detected to be removed by the
>>> mmc_detect_card_removed function, schedule a new detect work
>>> immediately and without a delay to let a rescan remove the
>>> card device as soon a possible. This will sooner prevent
>>> further I/O requests.
>>>
>>> Signed-off-by: Ulf Hansson <[email protected]>
>>> ---
>>> drivers/mmc/core/core.c | 16 ++++++++++++++--
>>> 1 files changed, 14 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
>>> index bec0bf2..265dfd8 100644
>>> --- a/drivers/mmc/core/core.c
>>> +++ b/drivers/mmc/core/core.c
>>> @@ -2077,6 +2077,7 @@ int _mmc_detect_card_removed(struct mmc_host *host)
>>> int mmc_detect_card_removed(struct mmc_host *host)
>>> {
>>> struct mmc_card *card = host->card;
>>> + int ret;
>>>
>>> WARN_ON(!host->claimed);
>>> /*
>>> @@ -2086,9 +2087,20 @@ int mmc_detect_card_removed(struct mmc_host *host)
>>> if (card && !host->detect_change && !(host->caps & MMC_CAP_NEEDS_POLL))
>>> return mmc_card_removed(card);
>>>
>>> - host->detect_change = 0;
>>
>> That line should not be removed. It is not related to your change.
>
> I think it is. Since my patch is trying to make it possible to "prevent I/O
> as soon as possible..."
No, the value of detect_change does not affect the outcome
if MMC_CAP2_DETECT_ON_ERR is set i.e.:
if (card && !host->detect_change && !(host->caps & MMC_CAP_NEEDS_POLL)
&& !(host->caps2 & MMC_CAP2_DETECT_ON_ERR))
is always false if (host->caps2 & MMC_CAP2_DETECT_ON_ERR) is true
>
> Clearing the detect_change flag here will prevent the I/O layer from doing
> further tests to see if the card is removed by using "mmc_detect_card_removed
> -> _mmc_detect_card_removed" due to the upper if sentence.
>
> I think this flag should only be cleared from the mmc_rescan function.
>
>>
>>> + ret = mmc_card_removed(card);
>>
>> Calling mmc_card_removed() is not needed here since
>> _mmc_detect_card_removed() does it anyway.
>>
>>> + if (!ret) {
>>> + ret = _mmc_detect_card_removed(host);
>>> + if (ret) {
>>> + /*
>>> + * Schedule a detect work as soon as possible to let a
>>> + * rescan handle the card removal.
>>> + */
>>> + cancel_delayed_work(&host->detect);
>>
>> Why cancel the detect work?
>
> To "prevent I/O as soon as possible...".
>
> The detect work could have been scheduled to be run at several ms later.
> There is no need to wait for it since we already now that card will be
> removed when the rescan function will execute.
>
>>
>>> + mmc_detect_change(host, 0);
>>> + }
>>> + }
>>>
>>> - return _mmc_detect_card_removed(host);
>>> + return ret;
>>> }
>>> EXPORT_SYMBOL(mmc_detect_card_removed);
>>>
>>
>>
>
> Br
> Ulf Hansson
>
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