Re: READ SCSI cmd seems to fail on SATA optical devices...

From: Arjan van de Ven
Date: Wed Nov 15 2006 - 11:21:48 EST


On Wed, 2006-11-15 at 11:17 -0500, Phillip Susi wrote:
> Tejun Heo wrote:
> >> The patch _seems_ to solve my problem. I am just really astonished when
> >> I read the diff file :D. Can I expect that it will be merged to the
> >> official kernel sources ?
> >
> > It seems that some devices choke when the bytes after CDB contain
> > garbage. I seem to recall that I read somewhere ATAPI device require
> > left command bytes cleared to zero but I can't find it anywhere now.
> > Maybe I'm just imagining. Anyways, yeah, I'll push it to upstream.
> >
>
> The original patch memsets the entire buffer only to copy over most of
> it right after. Could you amend the patch so that it memcpys first,
> then memsets only the remainder of the buffer? No sense wasting cpu
> cycles.

due to the funnies of how cpu caches work it might not actually be
faster though... Write Allocate and things like that are.. well fun.



--
if you want to mail me at work (you don't), use arjan (at) linux.intel.com
Test the interaction between Linux and your BIOS via http://www.linuxfirmwarekit.org

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/