Subject: Re: umass woe: sd0(umass0:0:0): readonly device & drive offline
To: Martin Husemann <>
From: Manuel Bouyer <>
List: tech-kern
Date: 11/18/2005 12:09:02
On Fri, Nov 18, 2005 at 12:05:22AM +0100, Martin Husemann wrote:
> On Thu, Nov 17, 2005 at 11:17:41PM +0100, Michael van Elst wrote:
> > We have devices that react erroneously when given a specific command.
> Where erroneously is not necessarily unrecoverable.
> > The correct solution is to not send the command
> Maybe, but maybe the easiest way to detect the situation is to send it
> and gracefully fail.

Ignoring all door lock errors is probably not a good idea on a device with
a real door.
However, in this case, if I remember properly (I don't have the whole thread
available in my mailbox) this specific device replies with a "illegal field
in CBD" sense code. With this error code it's clear that the device doesn't
supports it, and we can safely ignore the error (and add a flag in the
softc to not keep trying lock/unlock door for this device).

Manuel Bouyer <>
     NetBSD: 26 ans d'experience feront toujours la difference