3d0edb52b9
controller to be ready, but the drive attached to it may not be ready yet. Add a half a second delay before calling wdcattach(), to let the drive have its electronic ready to properly respond to the register tests done in wdcprobe1(). Delay based on experiments done by John Refling with various devices as part of the audit-trail of kern/25659; complete the fix for kern/25659.