We have an IOUserSCSIPeripheralDeviceType00 class DEXT supporting USB attached devices. With some high-capacity drives, the default setPowerState can exceed 20s to complete. This triggers a kernel panic, although this drive behavior is not unexpected.
With a kernel extension implementing similar functionality we see no such problem as it appears from reading of Apple open source the timeout was 100s.
What changes will allow setPowerState to complete without the kernel panic?
kernel panic report excerpt attached.
