On Fri, Aug 27, 2010 at 08:05:13PM +0100, Chris Ball wrote:
> Hi,
>
> On Fri, Dec 04, 2009 at 03:55:09PM +0800, r66093@xxxxxxxxxxxxx wrote:
> > From: Jerry Huang <Chang-Ming.Huang@xxxxxxxxxxxxx>
> >
> > Add callback function to check if the card has been removed.
> >
> > in order to check if the card has been removed, the function mmc_send_status will send commad CMD13 to card and ask the card to send its status register to driver, which will generate interrupt repeatly and make the system bad.
> > Therefore, get_cd callback is used to detect the card if the driver has.
> >
> > Signed-off-by: Jerry Huang <Chang-Ming.Huang@xxxxxxxxxxxxx>
> > ---
> > drivers/mmc/core/mmc.c | 5 ++++-
> > drivers/mmc/core/sd.c | 5 ++++-
> > 2 files changed, 8 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> > index 06084db..c5c676d 100644
> > --- a/drivers/mmc/core/mmc.c
> > +++ b/drivers/mmc/core/mmc.c
> > @@ -494,7 +494,10 @@ static void mmc_detect(struct mmc_host *host)
> > /*
> > * Just check if our card has been removed.
> > */
> > - err = mmc_send_status(host->card, NULL);
> > + if (host->ops->get_cd)
> > + err = !host->ops->get_cd(host);
> > + else
> > + err = mmc_send_status(host->card, NULL);
> >
> > mmc_release_host(host);
> >
> > diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
> > index cd81c39..3cf1f38 100644
> > --- a/drivers/mmc/core/sd.c
> > +++ b/drivers/mmc/core/sd.c
> > @@ -548,7 +548,10 @@ static void mmc_sd_detect(struct mmc_host *host)
> > /*
> > * Just check if our card has been removed.
> > */
> > - err = mmc_send_status(host->card, NULL);
> > + if (host->ops->get_cd)
> > + err = !host->ops->get_cd(host);
> > + else
> > + err = mmc_send_status(host->card, NULL);
> >
> > mmc_release_host(host);
> >
> > --
> > 1.6.4
>
> This patchset wasn't replied to -- any comments on it from the list?
I think this change makes sense, although it needs to be a bit smarter
with error handling because the get_cd() functions can return -ENOSYS if
they are not implemented (but the function pointer is still valid).
int err = 0;
if (host->ops->get_cd) {
err = host->ops->get_cd(host);
if (err >= 0)
err = !err;
}
if (!host->ops->get_cd || err < 0)
err = mmc_send_status(host->card, NULL);
Thoughts?
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