Messages in this thread |  | | | Date | Mon, 21 Jan 2002 12:32:43 +0100 | | From | Vojtech Pavlik <> | | Subject | Re: Linux 2.5.3-pre1-aia1 |
| |
On Mon, Jan 21, 2002 at 03:22:20AM -0800, Andre Hedrick wrote: > On Mon, 21 Jan 2002, Vojtech Pavlik wrote: > > > On Sun, Jan 20, 2002 at 04:12:36PM -0800, Andre Hedrick wrote: > > > > > > > > We only read out 4k thus the device has the the next 4k we may be wanting > > > > > > ready. Look at it as a dirty prefetch, but eventally the drive is going > > > > > > to want to go south, thus [lost interrupt] > > > > > > > > > > Even if the drive is programmed for 16 sectors in multi mode, it still > > > > > must honor lower transfer sizes. The fix I did was not to limit this, > > > > > but rather to only setup transfers for the amount of sectors in the > > > > > first chunk. This is indeed necessary now that we do not have a copy of > > > > > the request to fool around with. > > > > > > Listen and for just a second okay. > > > > > > Since the set multimode command is similar to the set transfer rate, if > > > you program the drive to run at U100 but the host can feed only U33 you > > > have problems. Much of this simple arguement is the same answer for > > > multimode. > > > > > > Same thing here but a variation, of the operations, > > > > So you're saying that if you program the drive to multimode 16, you > > can't read a single sector and always have to read 16? That not only > > doesn't make sense to me, but it also contradicts anything that I've > > heard before. > > Vojtech, > > If the device is programmed for to do 16 sectors in multimode, it and you > issue a read/write multiple pio and short change the device it is not > going to like it. However if it is programmed for multimode and you issue > single sector pio transfers command opcodes it is fine. > > Do we differ?
I think so. Check my mail from 11:14:56 GMT today. I fully understand that if I supply less data to the device than it expects or get less from it than it has, it'll be a problem. But I think the specification doesn't prohibit reading amounts not divisible by multimode setting via the multimode command. I've read it quite carefully again.
-- Vojtech Pavlik SuSE Labs - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
|  |