Messages in this thread | | | Date | Fri, 4 Apr 2003 17:13:56 +0200 | From | Jens Axboe <> | Subject | Re: [PATCH] only use 48-bit lba when necessary |
| |
On Fri, Apr 04 2003, Andries Brouwer wrote: > On Fri, Apr 04, 2003 at 02:29:36PM +0200, Jens Axboe wrote: > > > 48-bit lba has a non-significant overhead (twice the outb's, 12 instead > > s/non-// ?
Of course :)
> > of 6 per command), so it makes sense to use 28-bit lba commands whenever > > we can. > > > > > + if (drive->addressing == 1 && block > 0xfffffff) > > + lba48 = 1; > > Hmm. I wonder whether we should be more cautious, and ask for lba48 > as soon as some part of the interval is past this limit. > (say, block+nsectors > 0xfffffff) > > I don't know whether the standard spells out what happens > at the boundary, but for example the LBA low/mid/high, DEV is required > to contain the sector number at the place the error occurred, > and that is possible only if one stays below the 28-byte sector limit.
That might not be a bad idea, just to be on the safe side. I'll do that.
-- Jens Axboe
- 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/
| |