From: utzoo!decvax!ucbvax!info-vax Newsgroups: fa.info-vax Title: overlapped seeks Article-I.D.: ucbvax.7912 Posted: Mon Jul 5 23:51:20 1982 Received: Tue Jul 6 04:17:35 1982 >From dove@mit-dspg@mit-mc Mon Jul 5 23:50:55 1982 On an old emulex controller we had a problem with overlapped seeks. The problem was that the controller could interrupt due to seek completion even when a different drive was busy with a transfer. Since the driver assumed dec hardware which blocked such seek interrupts for the duration of the transfer, when it got the seek interrupt, it assumed that the transfer had completed, and everything broke! Our fix was to check in the interrupt routine for controller ready. If not, go to the end of the interrupt routine where the rmustart routine is called for each drive with as set.