Re: [PATCH v4] mmc: core: allow detection of locked cards

[Daniel Kucera <linux-mmc@danman.eu>]

On 2024-07-10 15:26, Ulf Hansson wrote:
> On Wed, 10 Jul 2024 at 07:21, Daniel Kucera <linux-mmc@danman.eu> 
> wrote:
>> 
>> On 2024-07-09 22:06, Avri Altman wrote:
>> >> If I understand correctly, there is no point in sending the CMD13
>> >> above, unless
>> >> this is the first attempt to initialize the card.
>> >> Therefore, it's better to move the whole part above, inside the below
>> >> if-clause
>> >> too, otherwise we would end up sending a CMD13 in cases when it's not
>> >> needed.
>> > R1_CARD_IS_LOCKED is CMD13 response, but already in CMD7 response as
>> > well,
>> > So theoretically you want to skip mmc_sd_setup_card altogether.
>> 
>> Do you mean to modify:
>> mmc_select_card(struct mmc_card *card)
>> to somehow return or save the R1 response to card struct?
> 
> I quite like this, as it avoids us from sending an unnecessary command
> during initialization.

Okay, but what if the host is SPI?

         if (!mmc_host_is_spi(host)) {
                 err = mmc_select_card(card);
                 if (err)
                         goto free_card;
         }

         err = mmc_sd_setup_card(host, card, oldcard != NULL);

> 
> A suggestion is to let  _mmc_select_card() take an additional
> out-parameter to provide the card's status. Then we can let
> mmc_select_card() parse the status - and if it finds that the card is
> locked, it can set a new state in card->state (similar to how we use
> MMC_STATE_BLOCKADDR, for example).
> 
> In another future step, we may also want to keep track of whether a
> locked card becomes unlocked. Using the card->state should work fine
> for that too, I think.
> 
> [...]
> 
> Kind regards
> Uffe