Re: ISDN massive packet drops while DVD burn/verify

Karsten Keil
2003-05-05T18:18:57Z

On Mon, May 05, 2003 at 07:26:52PM +0200, Stephan von Krawczynski wrote:
> On Mon, 5 May 2003 18:46:53 +0200
> Karsten Keil <kkeil@suse.de> wrote:
>
> > > How did we manage to become that bad?
> >
> > Its not so bad, the problem is how do you tune the system. If you prefer to
> > not interrupt the IDE transfers, which seems to be the default case, you
> > loose IRQ latency, which doesn't matter in much cases, but not on
> > this. You can tune it (hdparm work also with cdwriters, since
> > even if it use ide-scsi, the underlying driver is the ide driver.
>
> You mean UDMA 2 does not make it (which I had in the test case)?
>
> # hdparm -i /dev/hdc
>
> /dev/hdc:
>
> Model=SONY DVD RW DRU-500A, FwRev=2.0c, SerialNo=DA5B9D3D
> Config={ Fixed Removeable DTR<=5Mbs DTR>10Mbs nonMagnetic }
> RawCHS=0/0/0, TrkSize=0, SectSize=0, ECCbytes=0
> BuffType=unknown, BuffSize=0kB, MaxMultSect=0
> (maybe): CurCHS=0/0/0, CurSects=0, LBA=yes, LBAsects=0
> IORDY=on/off, tPIO={min:180,w/IORDY:120}, tDMA={min:120,rec:120}
> PIO modes: pio0 pio1 pio2 pio3 pio4
> DMA modes: mdma0 mdma1 mdma2
> UDMA modes: udma0 udma1 *udma2
> AdvancedPM=no
> Drive conforms to: device does not report version: 4 5 6
>

No the mode doesn't matter so much here, what give

hdparm -v /dev/hdc

> > This all don't say that here maybe also other problems around, but I have no
> > better explanation.
>
> Hm, this looks like the unresolved sleeping AVM Fritz2 syndrome to me: no idea
> of what's really going on ...

Hmm, don't remember this issue at the moment.

--
Karsten Keil
SuSE Labs
ISDN development