i.MX8MM Freeze

[felixradensky]

Hello,

Our i.MX8MM board comes with 2GB DDR4 RAM. We have used DDR4 RPA tool V10 to create DRAM configuration. We are experiencing system freezes during boot when Linux busfreq driver (drivers/soc/imx/busfreq-imx8mq.c) attempts to lower DDR frequency. The freeze is 100% reproducible on each boot. It occurs in both 4.14.98 and 4.19.35 BSP. We suspect that our DDR4 configuration may be a problem. The latest i.MX8MM DDR4 RPA tool V11 has limited the number of frequency points from 3 (2400, 400 and 100MHz) to 2 (2400 and 1336MHz). Is there any problem with 3 frequency points ?

Thanks.

Felix.

[felixradensky]

Hello,

We have tried running with DDR4 RPA V11 for the following PNs:

Samsung K4A8G165WC-BCTD  1GB DDR4 X2 chips on SOM
Micron MT40A1G16KNR-075-E  2GB DDP DDR4 x2 chips on SOM

Both pass the training and Stress Test with DDR Tool V3.1 but fail training under Sumo and Warrior in U-Boot for 633Mhz and 533MHz frequency points;

Should there be some parameters requiring adaptation ? RPA Tool sheets for both Samsung and Micron are attached.

Thanks.

[Jacob_bai]

Hi felixradensky ,

I am working on the VAR_SOM_IMX8MM too, and try to upgrade out 2GB DDR4 to 4GB DRAM. Before train the new 4GB dram, I just want to make sure I got serial download mode and DDR tool working well. I tried the generated ds file by MX8M_Mini_DDR4_RPA_v11 - Samsung 1GB.xlsx, but the the DDR tool got training failed. Any idea for that? Pls check the attached log file.

Regards,

Jacob

[oliver_chen]

Hi felixradensky‌,

Please also apply the rank-to-rank workaround on your DDR4 code.

B.R

Oliver