Re: [PATCH 2/4] sdhci: add quirk for broken sdio irq

[Olof Johansson <olof@lixom.net>]

On Wed, Dec 15, 2010 at 05:42:14AM -0500, zhangfei gao wrote:
> On Tue, Dec 14, 2010 at 11:49 PM, Olof Johansson <olof@lixom.net> wrote:
> > Some controllers can't handle SDIO IRQ properly. Give a way to
> > disable it.
> >
> > Signed-off-by: Olof Johansson <olof@lixom.net>
> > ---
> >  drivers/mmc/host/sdhci.c  |    6 +++++-
> >  include/linux/mmc/sdhci.h |    2 ++
> >  2 files changed, 7 insertions(+), 1 deletions(-)
> >
> > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> > index c0094c1..98f3d3d 100644
> > --- a/drivers/mmc/host/sdhci.c
> > +++ b/drivers/mmc/host/sdhci.c
> > @@ -1871,7 +1871,10 @@ int sdhci_add_host(struct sdhci_host *host)
> >                mmc->f_min = host->max_clk / SDHCI_MAX_DIV_SPEC_200;
> >
> >        mmc->f_max = host->max_clk;
> > -       mmc->caps |= MMC_CAP_SDIO_IRQ;
> > +       mmc->caps = 0;
> > +
> > +       if (!(host->quirks & SDHCI_QUIRK_NO_SDIO_IRQ))
> > +               mmc->caps |= MMC_CAP_SDIO_IRQ;
> >
> >        /*
> >         * A controller may support 8-bit width, but the board itself
> > diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h
> > index dfb2106..97d547e 100644
> > --- a/include/linux/mmc/sdhci.h
> > +++ b/include/linux/mmc/sdhci.h
> > @@ -85,6 +85,8 @@ struct sdhci_host {
> >  #define SDHCI_QUIRK_NO_HISPD_BIT                       (1<<29)
> >  /* Controller treats ADMA descriptors with length 0000h incorrectly */
> >  #define SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC           (1<<30)
> > +/* Controller should not use SDIO IRQ */
> > +#define SDHCI_QUIRK_NO_SDIO_IRQ                                (1<<31)
> 
> Just wander can we use another way instead of using the last two
> quirk, otherwise, no quirk can be used any more.
> If this is only tegra specific issue, any possibility to modify vector
> after add_host in sdhci-tegra.c.
> for example
> sdhci_add_host(host);
> host->mmc->max_seg_size = 65535;
> host->mmc->caps |= MMC_CAP_SDIO_IRQ;

Yuck. That completely breaks any kind of abstraction and layering.

> Really appreciate if not using the valuable quirk resource, which is u32.

No big deal. Next person that needs a quirk bit gets to bump the data
type to u64.


-Olof