> -----Original Message----- > From: Ulf Hansson [mailto:ulf.hansson@xxxxxxxxxx] > Sent: Wednesday, November 19, 2014 11:59 AM > To: Alex Lemberg > Cc: linux-mmc; Chris Ball; Avi Shchislowski > Subject: Re: [PATCH 1/1] Production State Awareness support in host side > > On 18 November 2014 19:41, Alex Lemberg <Alex.Lemberg@xxxxxxxxxxx> > wrote: > > Hi Ulf, > > > >> -----Original Message----- > >> From: Ulf Hansson [mailto:ulf.hansson@xxxxxxxxxx] > >> 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 > >> <avi.shchislowski@xxxxxxxxxxx> > >> 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!? According to eMMC spec, the switch to NORMAL should be done after device soldering to final host (not programmer). Please refer to "Figure 32 — Recommended Soldering procedure" in eMMC5.0 specification document. Also, since we are dealing with only "field" host here, we are not touching/switching any other modes of PSA, but only Normal (field). This code should run only once - in the beginning of device life cycle. Best regards, Alex > > Kind regards > Uffe ��.n��������+%������w��{.n�����{��i��)�� jg��� �����ݢj����G���� ���j:+v���w�m������w�������h�����٥
