Re: [PATCH] mmc: core: add auto bkops support

From: Ulf Hansson
Date: Mon Jun 27 2016 - 05:00:18 EST


[...]

>>>> one possible way is to control it by mmc-utils on
>>>> user space? So we should add a cmd for mmc-utils
>>>> there?
>>>
>>>
>>> That would be consistent with manual bkops.
>>>
>>
>>> From my first impression I agree, as that is the policy we have been
>>
>> sticking to when writing to persistent EXT_CSD persistent .
>> Although, in this case, I am actually wondering on what is the best
>> approach.
>
>
> I don't know what is the real meaning of "persistent". :)
> I don't know should we count auto bkops as the persistent
> registers....HS_TIMING and BUS_WIDTH should also be persistent
> registers as them are always used after initialization if not changing
> them?
>
> IHMO the more reasonable way is that:
> IIRC many settings for EXT_CSD should be OTP, like hw-reset(162),
> reliable write(167) fw-configure(169)..etc, which are marked as R/W.
> These should be controlled by userpace or even by firmware when
> flashing emmc, like reliable write...

Yes, that's makes sense to me. OTP registers must only be written to
via mmc utils/userspace.

>
>
> I'm not sure whether should I updete this $SUBJUCT or migirating it to
> userspace... We need to come to an agreement :)
>

I don't have any issue to allow all non-OTP registers bits to be written.

Kind regards
Uffe