On Wed, 2006-10-25 at 09:01 +0200, Hannes Reinecke wrote: > > What's the reason for having to have this hand crafted test unit ready? > > > I asked myself the same question. It's actually from the original > adaptec sources, and i couldn't figure out why it was need, either. > That's why I removed it initially when doing the first round of external > device reset patches. > > Thing is whenever we send a SCB with the MK_MESSAGE flag set the > sequencer will interrupt normal SCB delivery and ensure that the > MK_MESSAGE SCB is sent immediately. Plus we can force the connection to > non-packetized transfer as the resetted target will start out with > normal transfers, too. And as we already have invalidated the > negotiation settings for all targets a renegotiation will happen when > this TUR is completed. > So the normal flow of operation can continue and only one command will > have to be requeued from the midlayer. > > I think. Or that's what I've glanced from the sequencer code. Maybe Rob > can give some more insight here. > > Admittedly, this is really a nasty tweaking. In theory we should have a > proper error handler which handles this sort of thing. But the entire > code is littered with such tweakings so that's quite a vain hope. > Unless someone passes me a theory of operation document for it. > Having a register description is quite pointless. Yes ... that's what I was wondering. However, we can go with the "it's magic" for the time being. James - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
