Subject: Re: DVD-RAM: geometry & hangs
To: None <hubert.feyrer@informatik.fh-regensburg.de>
From: Eduardo E. Horvath <eeh@one-o.com>
List: tech-kern
Date: 11/17/1999 09:48:17
> thanks to Manuel and Eduardo, I've managet to get a bit further in this
> text adventure. :-) Now I have a kernel booting that recognizes the DVD
> RAM: 
> 
> sd1 at scsibus targ 4 lun 0: <MATSHITA, PD-2 LF-D100, A113> SCSI2 5/cdrom removable
> sd1: could not mode sense (4/5); using fictious geometry
> sd1: 595MB, 595 cyl, 64 head, 32 sec, 512 bytes/sect x 1218960 sectors

Are you sure it's a 512 bytes/sect device?  If it's not, the SCSI
controller could request a transfer of 1 sector (512 bytes), but the
drive could be trying to send 1 sector (2048 bytes).  If the driver
for the HBA does not handle overruns/underruns correctly it could
result in a hang as one side is waiting for data the other isn't
prepared to send or visa-versa.

=========================================================================
Eduardo Horvath				eeh@one-o.com
	"I need to find a pithy new quote." -- me