LSDK UserGuide Mismatch with Source Code

[Teruharu]

I have a LS1028ARDB and I'm trying to build kernel with TSN and RT support, so I'm following the LSDK-21.08 guide but found some problems.

The LSDKUG_Rev21.08 says there is one kernel config parameter with symbol "MSCC_FELIX_SWITCH_PTP_CLOCK", but I can't find it in kernel config file while all prefix met, it doesn't exist in Kconfig file with path "drivers/net/ethernet/mscc/Kconfig". UG says related config option should located at line 38 of Kconfig metioned above but the specific file only has 35 lines.

I've tried these ways to find out some details about this, and listed below:

Guess: Maybe is version related problem

• My current branch is LSDK-21.08-RT, problem exists, can't find MSCC_FELIX_SWITCH_PTP_CLOCK;
• Go to LSDK-21.08 and verify, problem exists, can't find MSCC_FELIX_SWITCH_PTP_CLOCK;
• Go to LSDK-20.12-V5.4-RT and verify, problem exists, can't find MSCC_FELIX_SWITCH_PTP_CLOCK;
• Go to LSDK-20.12-V5.4 and verify, problem exists, can't find MSCC_FELIX_SWITCH_PTP_CLOCK;
• Go to LSDK-20.12-V4.19 and verify, problem doesn't exist,  MSCC_FELIX_SWITCH_PTP_CLOCK located at line 40;
• Go to LSDK-20.04-V4.19-RT-update-290520 and verify, problem doesn't exist,  MSCC_FELIX_SWITCH_PTP_CLOCK located at line 40;
• Go to LSDK-20.04-V4.19-update-290520 and verify, problem doesn't exist,  MSCC_FELIX_SWITCH_PTP_CLOCK located at line 40;

Seems that all Kernel with version LSDK-V4.19 don't have this problem. All kernels without this problem have some features:

• Kconfig contains more config options, typically named "MSCC_FELIX_SWITCH", "MSCC_FELIX_SWITCH_PTP_CLOCK", "MSCC_FELIX_SWITCH_TSN";
• Makefile located at "drivers/net/ethernet/mscc/Makefile" contains more build rules about felix components;
• Path "drivers/net/ethernet/mscc" contains more source code with prefix of "felix_" in their name.
• I can't find same modifications in any other v4.19.xxx tag, it only exists in v4.19.xxx versions with "LSDK".

Here is my question:

1. Shall I just ignore the lack of parameter "MSCC_FELIX_SWITCH_PTP_CLOCK" if other related parameters have been set correctly? If not, could you please offer some procedures?
2. Is this (Kconfig and Makefile change, source code deletion) a normal update of linux kernel released by NXP? If not, are there any UserGuide or ApplicationNote documents?
3. Could you please update the UserGuide, or release a ReferenceGuide to help us avoid similar problems if possible? 

Thanks, and best wishes.

[yipingwang · Accepted solution]

1. You could ignore the lack of parameter "MSCC_FELIX_SWITCH_PTP_CLOCK", FELIX switch PTP clock support is open by default since Linux Kernel 5.4 release.

2. This is a normal release from NXP.

3. Yes, we will.

[Teruharu]

OK, thanks a lot