HGST was bought by WDC. Over the years, it has sold different drives
branded as HGST, WD or WDC. All of them need the HGST workaround of
sending 4k-sized packets (or multiples of 4k). And the ones that don't
really need this aren't broken by this change. Submitter is the vendor
who has tested these changes on a number of drives. I've simplified it
slightly, since we don't need additional vendors for this at this
time.
Submitted by: JacobBurley via github on behalf of WDC
Pull Request: https://github.com/freebsd/freebsd/pull/391