[PATCH 22/26] imx8m: ddr: Disable CA VREF Training for LPDDR4

[Stefano Babic]

Hi Tim,

On 24.03.21 22:25, Tim Harvey wrote:
> On Fri, Mar 19, 2021 at 12:31 AM Peng Fan (OSS) <peng.fan at oss.nxp.com> wrote:
>>
>> From: Ye Li <ye.li at nxp.com>
>>
>> Users reported LPDDR4 MR12 value is set to 0 during PHY training,
>> not the value from FSP timing structure, which cause compliance test failed.
>> The root cause is the CATrainOpt[0] is set to 1 in 2D FSP timing
>> but not set in 1D.  According to PHY training application node,
>> to enable the feature both 1D and 2D need set this field to 1,
>> otherwise the training result will be incorrect.
>> The PHY training doc also recommends to set CATrainOpt[0] to 0 to use
>> MR12 value from message block (FSP structure). So update the LPDDR4
>> scripts of all mscale to clear CATrainOpt[0].
> 
> Peng,
> 
> Is this issue being addressed by an update of the NXP i.MX 8M Family
> DDR Tools app that generates this code? Is there a reference to this
> issue online anywhere?
> 
> A bit unrelated but I would love to see NXP step up and replace the
> silly NXP i.MX 8M Family DDR Tools windows app with code that could be
> enabled in the SPL to do the same thing. Personally it's a bit of a
> joke to require having a Windows PC around to bring up an ARM
> processor board and I would hope there are folks at NXP that are
> utterly ashamed at this as well. One could easily use the opensource
> imx-usb-loader to load an SPL that performed this calibration and
> training code.

You find a lot of friends here....most of us will frankly be glad if 
there will be such as tool, or at least if some code is published to 
help to port to Linux. NXP story did not show a big interest in the past 
with the Windows-based MFGTools, but I hoped this was changed with 
"uuu". Such as tool will really help to improve i.MX support and enlarge 
NXP community (just a couple of notes: I do not expect Peng can decide 
this, but he can report our thought internally to NXP).

Best regards,
Stefano

-- 
=====================================================================
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: sbabic at denx.de
=====================================================================