i.MX6UL freezes when DDR3 bus enters low-power mode

[gonzalo_ruiz]

Hello Team,

We have experiencing an issue recently on our design that includes the i.MX6UL processor.

Some boards (but not all of them) freeze when the DDR3 bus enters low power mode and reduces its frequency to 24MHz. It appears the system is still alive but it is almost impossible to get anything from it. I managed to get a kernel messages dump, which I attach here.

I tried to run a stress test at that frequency on the failing units using the DDR Stress Tool, but 24MHz is out of the permitted frequency range of the test, so I couldn't.

Could you comment on what could be the cause and any possible test I could run to debug the problem and fix it?

Thank you very much for your support.

Regards,

Gonzalo

[nxf63675]

Hi @gonzalo_ruiz ,

You could try to run a MTEST on the u-boot interface, it should allow you to run a quick test on the DDR's.

Regards,

Israel H.

[gonzalo_ruiz]

Hi @nxf63675 ,

The MTEST doesn't throw any result since the units only show the error when the DDR enters low power mode, and the DDR is operating on a normal state (400MHz) on U-Boot.

What could be the cause for this error?

Any other way to run a DDR stress test at the selected frequency?

Regards,

Gonzalo