Re: [Cdrdao-devel] ide-scsi driver extremely buggy ; cdrecord atapi support?

[Keenan T. <kt...@go...>]

That did the trick, I'm now burning at full speed with 2.5.67-ac.=20
Thanks a lot for the pointers.

On Mon, 2003-04-28 at 16:03, Giuseppe Corbelli wrote:
> On Sun, Apr 27, 2003 at 08:31:02PM -0600, Keenan Tims wrote:
> > > > I've got a rather major issue with the ide-scsi driver: it uses 100=
%
> > > > cpu, and is constantly buffer underrunning etc. due to the kernel n=
ot
> > > > using DMA (I believe...this is what I have found by extensive searc=
hing)
> > > > for ide-scsi io with odd blocksizes.  cdrecord, on the other hand, =
works
> > > > without issue with the native ATAPI support in 2.x.  You're using
> > > > schilly's libscg if I remember correctly...so I'm assuming it would=
 be a
> > > > very easy update to include this support into cdrdao so I can burn =
at
> > > > high speeds wtih cdrdao too ;)  I built from CVS today, and
> > > > unfortunately this support doesn't seem to be included yet.  Are th=
ere
> > > > plans to build this in?  What's the timeline on such support?
> > > I haven't heard from the author for a while. You probably can do the =
work
> > > yourself by replacing the library code in cdrdao with cdrecord's one.
> > > But I would suggest you to try harder with the DMA.
> >=20
> > Do you have any suggestions in this regard?  DMA seems to be used for
> > normal CD access, but not writing.  I've played around with
> > /proc/ide/hdd/settings, it shows that the drive is using dma at 33MB/s
> > (as does /proc/ide/via).  I've tried messing around with the
> > current_speed value, and using_dma as well as some of the others.  I'm
> > convinced the kernel is using PIO writes for ide-scsi though.  Doing a
> > 'time' on the cdrecord shows that about 75% of the real time used is
> > spent in system calls.  Using ATAPI it's less than 1%.  The problem is
> > that ATAPI is buggy in 2.4.20, and 2.5.68 is really unstable for me.  I=
f
> > I could get such support in cdrdao I could be happy with it, I'd spend
> > some time finding a stable devel kernel.  But I'm a rather poor C coder=
,
> > I think this is somewhat beyond me.  I took a gander at the code, but I
> > can't even find what'd need replacing, let alone actually doing it.
> Well then, if you're sure that you're using DMA I have no furter info. I
> don't have proper hardware to do some test.
> Schilling SCSI access library used by cdrdao is located in scsilib/ dir.
> Just replacing what's here (and perhaps some symlinks into scsilib/export=
)
> with the new library from cdrtools should do. At least I've done this in =
the
> past w/o trouble. You may also try with the configure switches.
--=20
Keenan Tims
kt...@go...
PGP: http://www.gotroot.ca/pubkey.txt