Re: [PATCH 2/2] mmc: dw_mmc: add hw_reset extension hook

[Shawn Lin]

On 2015/10/22 17:48, Ulf Hansson wrote:
> On 22 October 2015 at 08:19, Shawn Lin <shawn.lin@xxxxxxxxxxxxxx> wrote:
> > This patch add hw_reset for dw_mmc to implement hw reset
> > procedure. It's useful for mmc core to recover emmc devices
> > if emmc runs into unexpected state. Add MMC_CAP_HW_RESET
> > capability to dw_mmc extension driver directly if it needs hw_reset.
> >
> > Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
> > ---
> >
> >   drivers/mmc/host/dw_mmc.c | 4 ++++
> >   drivers/mmc/host/dw_mmc.h | 2 ++
> >   2 files changed, 6 insertions(+)
> >
> > diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> > index 8a0f2995..46b12de 100644
> > --- a/drivers/mmc/host/dw_mmc.c
> > +++ b/drivers/mmc/host/dw_mmc.c
> > @@ -1482,6 +1482,10 @@ static void dw_mci_hw_reset(struct mmc_host *mmc)
> >   {
> >          struct dw_mci_slot *slot = mmc_priv(mmc);
> >          struct dw_mci *host = slot->host;
> > +       const struct dw_mci_drv_data *drv_data = host->drv_data;
> > +
> > +       if (drv_data && drv_data->hw_reset)
> > +               return drv_data->hw_reset(host);
>
> dw_mmc is starting to walk the same bad path as sdhci has done.
>
> Please, try to avoid adding non-needed callbacks and start to turn
> dw_mmc into a library instead.

sorry for posting this, but then a I am just now reading your comments 
about overstaffed quirks and callback of sdhci. Obviously dw_mmc is a 
little easier to be turned into a lib before it going to be the 
equivalent weight of sdhci.

I'm glad to try it. :)

> Kind regards
> Uffe
>
> >          if (host->use_dma == TRANS_MODE_IDMAC)
> >                  dw_mci_idmac_reset(host);
> > diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
> > index 9df18c1..21b9df4 100644
> > --- a/drivers/mmc/host/dw_mmc.h
> > +++ b/drivers/mmc/host/dw_mmc.h
> > @@ -282,6 +282,7 @@ struct dw_mci_slot {
> >    * @set_ios: handle bus specific extensions.
> >    * @parse_dt: parse implementation specific device tree properties.
> >    * @execute_tuning: implementation specific tuning procedure.
> > + * @hw_reset: implementation specific hw reset procedure.
> >    *
> >    * Provide controller implementation specific extensions. The usage of this
> >    * data structure is fully optional and usage of each member in this structure
> > @@ -299,5 +300,6 @@ struct dw_mci_drv_data {
> >                                                  struct mmc_ios *ios);
> >          int             (*switch_voltage)(struct mmc_host *mmc,
> >                                            struct mmc_ios *ios);
> > +       void            (*hw_reset)(struct dw_mci *host);
> >   };
> >   #endif /* _DW_MMC_H_ */
> > --
> > 2.3.7


--
Best Regards
Shawn Lin

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