On Fri, 17 Jun 2022, cym@rock-chips.com wrote:
Could you help us to get the DRAM part number which initialization failures on the Rock Pi 4+.
I have tested 3 boards; one appears to be fully working, on another 1 of the 2 LPDDR4 (Channel 1) chips consistently fails with a Col and Cap Error and on the final one both chips (Channel 0 & 1) fail in the same way as the last (Col and Cap errors).
All chips are: H9HCNNNBKUML
We have found that some LPDDR4 abnormal operation at 50MHz. I think you can try that use 400MHz to detect capacity.
Wonderful. This solves the problem. Thank you so much!
Would you like to submit this into upstream U-boot yourself, or would you like me to do that for you?
If the former, please Cc me on the patch and add my:
Tested-by Lee Jones lee.jones@linaro.org
If the latter, please let me know and I'll do what I can to help.