T440P: Unable to initialize memory speeds above 1600 MT/s

I just bought a pair of HyperX DDR3L-2133 CL11 memory. They are supported and run fine at 2133 MT/s with the original Lenovo firmware.

However Coreboot only registers them at 1600 MT/s.

Changing the value of .max_ddr3_freq to 2133 in src/mainboard/lenovo/t440p/romstage.c leads to a bricked notebook. A beeping sound occurs, regardless of the installed memory type (1600 or 2133).

[Arthur Heymans]

[e-mail] writes:
> I just bought a pair of HyperX DDR3L-2133 CL11 memory. They are supported and run fine at 2133 MT/s with the original Lenovo firmware.
> However Coreboot only registers them at 1600 MT/s.
>
> Changing the value of .max_ddr3_freq to 2133 in src/mainboard/lenovo/t440p/romstage.c leads to a bricked notebook. A beeping sound occurs, regardless of the installed memory type (1600 or 2133).

Looking at src/northbridge/intel/haswell/pei_data.h The only valid
values are 800, 1067, 1333, 1600 for the mrc.bin. The sandybridge code
with a similar PEI/mrc.bin is better at guarding against invalid
values. Maybe that code should be adapted to haswell.

1600MT/s is what the controller officially supports. Anything faster is
overclocking and the mrc.bin likely does not support that.

After cherry picking a few dozen commits of the brilliant mythbk and following his suggestions I was able to get it up and running.

https://github.com/archfan/coreboot/commit/bd3e5cf5c8277dbb286ec4234e0355afe...
> 1600MT/s is what the controller officially supports. Anything faster is

overclocking and the mrc.bin likely does not support that.

Correct. There is a hard coded limit of 1600 MT/s in the mrc.bin.