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From: (Joerg Schilling)
Subject: Re: Again... DMA speed too slow
Date: Mon, 14 Apr 2008 20:21:30 +0200	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <20080414182918.4779b8ea@core>

Alan Cox <> wrote:

> > OK, I know that a few drives give wrong DMA speed test results on Solaris,
> > so the behavior for these drives seems to be unrelated to the OS.
> Controllers don't always get DMA ATAPI right things like that - not
> trivial little speed test details.

Using the term "controller" is not specific enough to understand what you might
like to tell.

> > I am not sure why you mention the term "brave", is it because all known Linux 
> > distributions still require suid root? In this case, I encourage you to inform
> Last time I checked almost all cd burning was being done non root.

Looks like you are incorrectly informed in this area or you checked only software 
that does not work correclty in all cases ....

For your information:

Linux traditionally needed suid root for sending SCSI commands until someone 
introduced a bug in late 2.4 kernels. After this bug has been discovered, the 
Linux Kernel interface has been changed in an incomatible way. At the same time,
the Linux kernel started to filter SCSI commands. Some commands that are needed 
for CD/DVD writing still need root privileges, others don't.

Some people did take my working software and removed security checks.
The fact that it is possible to still write CDs under some conditions
does not prove anything. It justs verifies that the people who removed
those checks are not smart enough to find the assignements of the SCSI command
codes in cdrecord ;-)


-- (home) Jörg Schilling D-13353 Berlin                (uni)     (work) Blog:

  parent reply	other threads:[~2008-04-14 18:24 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-04-14 16:54 Joerg Schilling
2008-04-14 16:56 ` Alan Cox
2008-04-14 17:19   ` Joerg Schilling
2008-04-14 17:29     ` Alan Cox
2008-04-14 17:44       ` Alan
2008-04-14 18:28         ` Joerg Schilling
2008-04-14 18:21       ` Joerg Schilling [this message]
     [not found] <>
2008-03-31  0:59 ` Robert Hancock
  -- strict thread matches above, loose matches on Subject: below --
2008-03-30 21:53 J.A. Magallón
2008-04-02  7:16 ` Andrew Morton
2008-04-13  2:23   ` Tejun Heo

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