Re: [RFC PATCH] mmc: Enable wakeup_sources for mmc core

[Ulf Hansson]

On 19 June 2013 19:29, Colin Cross <ccross@xxxxxxxxxxx> wrote:
> On Wed, Jun 19, 2013 at 7:21 AM, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote:
>> It seems like a bad idea that an insertion of an SD card should
>> trigger the display to be light up. That is indirectly in principle
>> what you suggest should happen from user space once a new SD card is
>> found. Right?
>
> Most likely what will happen is the system will mount the sdcard, and
> if necessary start the media scanner so that the user can see their
> media on the sd card when they turn the screen on.  But that is mostly
> irrelevant, the point is that the event needs to be passed to
> userspace to allow it to make the decision in a timely fashion.
>
>> I have been working with Android for several years, we never used this
>> kind of setup. Instead we wait for the user to press the "display on"
>> button. At that time the confirmation will be received. Not saying
>> that this is the only way of doing it, but it seems to be an accepted
>> solution for all our customers.
>
> This patch is ported from the Android common tree, so you've probably
> been using it.

We removed more or less all Android code in the mmc subsystem, since
it just didn't work. :-)

The "deferred resume" was very useful though, so after some rework we
kept it and could then improve the system resume time significantly.

>
>> I agree to that this patch should have negligible impact though - if
>> we get things right. I will try to review the code in more detail
>> soon.
>>
>> Kind regards
>> Ulf Hansson
>>
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