Re: [PATCH v3] mmc: core: allow detection of locked cards

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

Hi Avri,

On 2024-06-02 14:59, Avri Altman wrote:
>> Hello Avri,
>> 
>> On 2024-06-02 07:26, Avri Altman wrote:
>> >> On 2024-05-23 15:20, linux-mmc@danman.eu wrote:
>> >> > From: Daniel Kucera <linux-mmc@danman.eu>
>> >> >
>> >> > Locked card will not reply to SEND_SCR or SD_STATUS commands so it
>> >> > was failing to initialize previously. When skipped, the card will
>> >> > get initialized and CMD42 can be sent using ioctl to unlock the
>> >> > card or remove password protection.
>> >> > Until unlocked, all read/write calls will timeout.
>> >> >
>> >> > Signed-off-by: Daniel Kucera <linux-mmc@danman.eu>
>> >> > ---
>> >> >  drivers/mmc/core/sd.c | 13 ++++++++++++-
>> >> >  1 file changed, 12 insertions(+), 1 deletion(-)
>> >> >
>> >> > diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index
>> >> > 1c8148cdd..ae821df7d 100644
>> >> > --- a/drivers/mmc/core/sd.c
>> >> > +++ b/drivers/mmc/core/sd.c
>> >> > @@ -928,8 +928,19 @@ int mmc_sd_setup_card(struct mmc_host *host,
>> >> > struct mmc_card *card,
>> >> >       bool reinit)
>> >> >  {
>> >> >       int err;
>> >> > +     u32 card_status;
>> >> >
>> >> > -     if (!reinit) {
>> >> > +     err = mmc_send_status(card, &card_status);
>> >> > +     if (err){
>> >> > +             pr_err("%s: unable to get card status\n", mmc_hostname(host));
>> >> > +             return err;
>> >> > +     }
>> >> > +
>> >> > +     if (card_status & R1_CARD_IS_LOCKED){
>> >> > +             pr_warn("%s: card is locked\n", mmc_hostname(host));
>> >> > +     }
>> >> > +
>> >> > +     if (!reinit && !(card_status & R1_CARD_IS_LOCKED)) {
>> >> >               /*
>> >> >                * Fetch SCR from card.
>> >> >                */
>> >>
>> >> Any feedback please?
>> > You didn't address my comment from your v1 - Since eMMC & SD shares
>> > the very same locking feature (non-COP SD that
>> > is) -
>> > You should at least explain in your commit log why it isn't an issue
>> > for eMMC, If indeed it is not.
>> 
>> I'm sorry, I didn't get what you mean by that. I am touching only the 
>> sd.c code, not
>> the mmc.c (where eMMC is initialized, am I correct?).
>> How should I address this?
>> Should I test with eMMC to SD adaptor? I don't have any currently.
> Theoretically, looking in the eMMC spec, a locked eMMC device
> shouldn't have any issue returning from power down.
> The only flow that is affected is that its not allowed to switch to
> hs200 in a locked state until unlocked - not to say that it is a
> problem.
> If you can't verify that via code review,  can you test your mmc-utils
> code on an eMMC platform?

I've just tested with an eMMC to SD adapter in my reader and it is 
detected correctly:

[1463181.072006] mmc1: unexpected status 0x2000900 after switch
[1463181.074560] mmc1: unexpected status 0x2000900 after switch
[1463181.077038] mmc1: unexpected status 0x2000900 after switch
[1463181.079709] mmc1: unexpected status 0x2000900 after switch
[1463181.081972] mmc1: unexpected status 0x2000900 after switch
[1463181.083412] mmc1: unexpected status 0x2000900 after switch
[1463181.084831] mmc1: unexpected status 0x2000900 after switch
[1463181.084836] mmc1: new high speed MMC card at address 0001
[1463181.085195] mmcblk1: mmc1:0001 004GA0 2.59 GiB

Do I need to do some changes to the patch?

> 
> Thanks,
> Avri
>> 
>> I am sorry if these are stupid questions, I am a layman.
>> 
>> >
>> > Thanks,
>> > Avri
>> >
>> >>
>> >> D.
>> 
>> Thank you.
>> Daniel.

Thank you,
Daniel