Reducing unnecessary calibration of a memory unit for which the error count margin has been exceeded

A data storage system, comprising:

• a controller for a non-volatile memory, wherein the controller is configured to:
• set an error count margin for each of multiple units of the non-volatile memory;
• detect whether the error count margin of any of the multiple units has been exceeded;
• in response to detecting that the error count margin of a memory unit among the multiple memory units is exceeded, determine whether calibration of the memory unit would improve a bit error rate of the memory unit sufficiently to warrant calibration;
• and
• perform calibration of the memory unit in response to determining that calibration of the memory unit would improve the bit error rate of the memory unit sufficiently to warrant calibration.

A computer program product, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a controller to cause the controller to perform:

• setting an error count margin for each of multiple units of the non-volatile memory;
• detecting whether the error count margin of any of the multiple units has been exceeded;
• in response to detecting that the error count margin of a memory unit among the multiple memory units is exceeded, determining whether calibration of the memory unit would improve a bit error rate of the memory unit sufficiently to warrant calibration;
• and
• performing calibration of the memory unit in response to determining that calibration of the memory unit would improve the bit error rate of the memory unit sufficiently to warrant calibration.