Re: ISDN massive packet drops while DVD burn/verify

[Karsten Keil <kkeil@suse.de>]

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