On 18 November 2014 19:41, Alex Lemberg <[email protected]> wrote:
> Hi Ulf,
>
>> -----Original Message-----
>> From: Ulf Hansson [mailto:[email protected]]
>> Sent: Monday, November 17, 2014 3:34 PM
>> To: Avi Shchislowski
>> Cc: linux-mmc; Chris Ball; Alex Lemberg
>> Subject: Re: [PATCH 1/1] Production State Awareness support in host side
>>
>> On 17 November 2014 13:52, Avi Shchislowski <[email protected]>
>> wrote:
>> > Adding support for PSA (Production State Awareness) feature for all
>> > eMMC devices with revision >=5.0 In this patch the eMMC driver will
>> > check if device was completed its Production State mode, and will
>> > switch it to Normal (field) mode.
>> > Switching to normal mode signal the device to complete its work in
>> > production mode and start working in regular performance mode.
>>
>> Please add some detail to what this patch does. Additionally why it's needed.
>
> In this patch driver should recognize if eMMC device (Rev >=5.0) was not 
> switched
> to Normal (0x00) PSA mode by storage vendor or Programmer house.
> For this, we are checking if device was leaved in PRE_SOLDERING_POST_WRITES 
> (0x02)
> state - represents a state in which the device is in production and the host
> (usually programmer) completed to load the content to the device.
> The host (usually programmer) sets the device to this state after content was 
> loaded
> and just before soldering.
> After soldering the device to real host (not programmer), the device should 
> be switched to
> Normal (0x00) mode.
> The Normal (0x00) mode of PSA register represents a state in which the device 
> is running
> in the field and uses “regular” operations.
> Leaving device in PRE_SOLDERING_POST_WRITES (0x02) might not allow to host 
> write content
> to the device.
>
> More details about PSA feature can be found in eMMC 5.0 spec (Jedec:
>  JESD84-B50.pdf)
> http://www.jedec.org/standards-documents/technology-focus-areas/flash-memory-ssds-ufs-emmc/e-mmc
>
> Please let us know if more details required.

Okay, that was far better.

I am not so sure we should finalize the production phase while
initializing the eMMC card like this.

Certainly we should check the PSA state, but I think we should return
an error if we think the device hasn’t completed production. It should
be the responsibility for the "programming tools" to finalize the
production, right!?

Kind regards
Uffe
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