RE: [PATCH] mmc: block: Differentiate busy and non-TRAN state

From: Avri Altman
Date: Wed Jul 07 2021 - 02:49:07 EST


Hi,
> >What exactly are you trying to do with the user space program through
> >the mmc ioctl with all these commands? The mmc ioctl interface is not
> >designed to be used like that.
> >
> >In principle, it looks like we should support a complete
> >re-initialization of the card. I am sorry, but no thanks! This doesn't
> >work, but more importantly, this should be managed solely by the
> >kernel, in my opinion.
>
> Doing initialization itself through ioctl is silly, I agree, and does
> not work on other ends. This patch is not about that. it just explicitly disables
> any CMD13 polling for TRAN for some of those commands. the behavior
> for such commands thus is the same as without the patch.
> The reason for this patch is to not run into the race condition that a
> following (ioctl) command will be rejected because the card is in e.g. PROG
> state
> of a previous ioctl command. As stated earlier, I encountered this a lot when
> doing a unlock force erase -> lock/set, in both scenarios, issued as two single
> ioctl commands and bundled together.
Are you using mmc-utils?
Can you share exactly the sequence of commands you are sending?

> But this race condition exists on any (non-R1b/ RPBM) currently. As there is
> no CMD13 polling happening after the response (or whenever the driver
> marks
> the request as done), the card's status is therefore generally unknown.
Again, can you share the sequence of the commands you are using?

Thanks,
Avri

>
> So in short I don;t want to do anything too crazy from userspace, but the
> alternative now is to do like 100ms sleeps in the hope that the card is
> actually finished with the issued command (not just the host driver so to
> say).
>
> Kind Regards,
> Christian
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