Re: [PATCH V5 02/15] mmc: core: Enable / disable re-tuning

[Adrian Hunter <adrian.hunter@intel.com>]

On 16/04/15 11:57, Ulf Hansson wrote:
> On 14 April 2015 at 15:12, Adrian Hunter <adrian.hunter@intel.com> wrote:
>> Enable re-tuning when tuning is executed and
>> disable re-tuning when card is no longer initialized.
>>
>> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
>> ---
>>  drivers/mmc/core/core.c | 4 ++++
>>  1 file changed, 4 insertions(+)
>>
>> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
>> index c296bc0..dd43f9b 100644
>> --- a/drivers/mmc/core/core.c
>> +++ b/drivers/mmc/core/core.c
>> @@ -1109,6 +1109,8 @@ int mmc_execute_tuning(struct mmc_card *card)
>>
>>         if (err)
>>                 pr_err("%s: tuning execution failed\n", mmc_hostname(host));
>> +       else
>> +               mmc_retune_enable(host);
>>
>>         return err;
>>  }
>> @@ -1140,6 +1142,8 @@ void mmc_set_bus_width(struct mmc_host *host, unsigned int width)
>>   */
>>  void mmc_set_initial_state(struct mmc_host *host)
>>  {
>> +       mmc_retune_disable(host);
>> +
>>         if (mmc_host_is_spi(host))
>>                 host->ios.chip_select = MMC_CS_HIGH;
>>         else
>> --
>> 1.9.1
> 
> I don't think you have fully considered these cases for the mmc/sd/sdio cards.

Thanks for look at this, but I don't see a problem - see below.

> 
> 1) Card removal/detect (hold/release?)

Re-tuning will be done if needed before detect (because it is done before a
request), which is necessary because detect can fail if tuning is needed.

Re-tuning is done before a request. Requests aren't started if the card has
been removed i.e. mmc_start_request() calls mmc_card_removed()

If tuning is executed while a card is being removed, then the tuning will
fail and the request will be errored out.

> 2) system PM (disable?)

System pm does mmc_power_off() which calls mmc_set_initial_state()

> 3) runtime PM (disable?)

If the card powers off then mmc_set_initial_state() will called.

For anything else the card might be doing, the mmc_retune_hold() /
mmc_retune_release() functions are used.

> 4) reset (?)

Reset goes through mmc_set_initial_state()