Re: CDROM bug in 2.3.x

Jens Axboe (axboe@image.dk)
Wed, 1 Sep 1999 15:48:36 +0200


On Wed, Sep 01 1999, David S. Miller wrote:
> This one has been there for a while, and I finally sat
> down just now to track it down.
>
> What I see is that the generic cdrom driver is passing
> down packet commands with a buffer length which is
> negative. I see that some of the cgc command building
> routines are setting negative buffer lengths on purpose.
>
> This is illegal and is confusing SCSI drivers quite
> badly, because the scsi command will have
> SCpnt->request_bufflen < 0 and this will be given to
> the controller for the DMA request.
>
> I don't know what the intentions were here, but this
> does need to be fixed somehow so I leave it to Jens
> to figure out the correct fix.

It sets the negative buflens for the ide-cd driver,
which otherwise assumes that the transfer is going
in the wrong directions. It did seem odd to me at
first, but I wasn't aware that the SCSI drivers
got confused. I'll fix it up.

> Thanks.
>
> Later,
> David S. Miller
> davem@redhat.com

-- 
*  Jens Axboe <axboe@image.dk>
*  Linux CD-ROM Maintainer
*  http://www.kernel.dk

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