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

[Shawn Lin <shawn.lin@rock-chips.com>]

On 2015/10/22 17:48, Ulf Hansson wrote:
> On 22 October 2015 at 08:19, Shawn Lin <shawn.lin@rock-chips.com> 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@rock-chips.com>
>> ---
>>
>>   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