Symptom

Changing data bits(7) and stop bits(2) in BIOS Advanced -> Console redirection settings option (COM1 "Data Bits" and "Stop Bits") results in garbled code in the Putty serial console output.

Restarting the POST interface should allow normal display without garbled code.

Affected Configurations

The system may be any of the following Lenovo servers:

• ThinkSystem SR635, Type 7Y98, any model
• ThinkSystem SR635, Type 7Y99, any model
• ThinkSystem SR655, Type 7Y00, any model
• ThinkSystem SR655, Type 7Z01, any model

This tip is not software specific.

This tip is not option specific.

The system has the symptom described above.

Solution

This behavior will be corrected in a future release of Baseboard Management Controller (BMC).

The target date for this release is scheduled for Third Quarter 2021.

The file is or will be available by selecting the appropriate Product Group, type of System, Product name, Product machine type, and Operating system on Lenovo Support web page, at the following URL:

http://datacentersupport.lenovo.com/

Workaround

Keep the original data/stop bits settings as 8/1 in putty console.

Additional Information

The rear system com port configuration in AMD Fch does not take effect or will be altered back from BMC's UART initialization process.