WF_PID_MAX_HISTORY
s32 samples[WF_PID_MAX_HISTORY]; /* samples history buffer */
s32 errors[WF_PID_MAX_HISTORY]; /* error history buffer */
s32 powers[WF_PID_MAX_HISTORY]; /* power history buffer */
s32 errors[WF_PID_MAX_HISTORY]; /* error history buffer */
hsize = min_t(int, mpu->tguardband, WF_PID_MAX_HISTORY);
hsize = min_t(int, mpu->tguardband, WF_PID_MAX_HISTORY);