[PATCH] mmc: core: add auto bkops support

Ulf Hansson ulf.hansson at linaro.org
Wed Jun 22 08:03:57 PDT 2016


[...]

>>> >From my first impression I agree, as that is the policy we have been
>>>>sticking to when writing to persistent EXT_CSD registers.
>>>>Although, in this case, I am actually wondering on what is the best approach.
>>>>
>>>>Is there really ever a case when we don't want auto BKOPS to be default enabled?
>>>>I think BKOPS is a fundamental feature of an FTL and I can't see a
>>>>reason to why we need to involve mmc-utils/userspace to enable it. Am
>>>>I wrong?
>>>
>>> The even worst case is – involve mmc-utils/userspace to DISABLE it.
>>> I think this register need to be set by vendor and no need to be changed on runtime.
>>
>>If it is set by the Vendor, that's of course the best.
>
> It can be set by Storage Vendor.
> According to the spec, the default value of this bit is vendor specific.
>
>>
>>Are you saying that we shouldn't enable it during the card init
>>sequence from the kernel, in case it is disabled?
>
> No.
> By the spec – a Host that wants to enable the device to perform
> background operations during device idle time, should signal the
> device by setting AUTO_EN in BKOPS_EN field [EXT_CSD byte 163] to 1b.

Okay, thanks!

Kind regards
Uffe



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