Ulf,

On Wed, Aug 27, 2014 at 4:17 AM, Ulf Hansson [off-list ref] wrote:

quoted

Now, we've got MMC_CAP_NEEDS_POLL, so dw_mmc will periodically be
called to check the card detect line, but with vmmc and vqmmc off.  It
will be unable to return a sensible value without actually turning on
vmmc and vqmmc.

Currently MMC_CAP_NEEDS_POLL mean the mmc rescan work will reschedule
itself with HZ interval. This to check for card insert/removal.

Now, mmc_rescan() will, if present, invoke host's ->get_cd() callback
to check whether it's worth to continue initialization sequence or if
it should re-schedule itself again.

If your host driver can distinguish whether a card is inserted, which
in this case are when vccq is turned off, your ->get_cd() callback need
to return 1. That will allow mmc_rescan() to continue it's
initialization sequence and do mmc_power_up().

As per my other email, we can't tell whether a card is inserted when
vqmmc is off.

Does this mean that you have removed your objections to a solution
like Yuvaraj has posted?  We still need to break it into two patches
(the core part and the dwmmc part), but otherwise is it OK?  I can
post the original patch I sent Yuvaraj if it's helpful (or he can just
include my patch as part 1 of his series).

-Doug