RE: [PATCH] mmc: core: resume not check card exist before powerup

[Ricky WU <ricky_wu@realtek.com>]

Soft reminder

If this solution, you still have concert on sd.c.
can we just do this check card flow in mmc host power up call_back? 

> > >
> > > _mmc_sd_resume
> > > add get_cd before call powerup, make sure the card exist
> >
> > Please elaborate more on what problem you are trying to solve, the
> > above doesn't make much sense to me, sorry.
> >
> > Yes, the card may be removed while the system is suspended. Then, even
> > if ->get_cd() indicates that there is no card inserted in the
> > SD-card-slot, we may still have the card being registered - and then
> > we need to unregister it.
> > That said, we need to call mmc_power_up() in order to try to
> > communicate with the card again. At least that is what the
> > mmc_rescan() work assumes when it runs the bus_ops->detect() callback
> > at some point later in time.
> >
> 
> We saw the power up in a short time from waveform when removing the card,
> So we saw mmc_sd_resume call the power up did not check the card exist.
> 
> We think this the short time power up maybe cause OCP if no card exist.
> And this power up we think is unnecessary when no card exist.
> 
> 
> > >
> > > Signed-off-by: Ricky Wu <ricky_wu@realtek.com>
> > > ---
> > >  drivers/mmc/core/sd.c | 3 +++
> > >  1 file changed, 3 insertions(+)
> > >
> > > diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index
> > > 1c8148cdda50..35e036672cfb 100644
> > > --- a/drivers/mmc/core/sd.c
> > > +++ b/drivers/mmc/core/sd.c
> > > @@ -1750,6 +1750,9 @@ static int _mmc_sd_resume(struct mmc_host
> > *host)
> > >         if (!mmc_card_suspended(host->card))
> > >                 goto out;
> > >
> > > +       if (host->ops->get_cd && !host->ops->get_cd(host))
> > > +               goto out;
> > > +
> > >         mmc_power_up(host, host->card->ocr);
> > >         err = mmc_sd_init_card(host, host->card->ocr, host->card);
> > >         mmc_card_clr_suspended(host->card);
> > > --
> > > 2.25.1
> > >
> >
> > Kind regards
> > Uffe