Messages in this thread | | | From | Joerg Schilling <> | Date | Thu, 26 Jan 2006 10:50:52 +0100 | Subject | Re: CD writing in future Linux (stirring up a hornets' nest) |
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Matthias Andree <matthias.andree@gmx.de> wrote:
> Joerg Schilling wrote: > > >> So I'll repeat my question: is there anything that SG_IO to /dev/hd* (via > >> ide-cd) cannot do that it can do via /dev/sg*? Device enumeration doesn't count. > > > > But device enumeration is the central point when implementing -scanbus. > > Again: Is there anything *besides* (<German>: außer) device enumeration that > does not work with the current /dev/hd* SG_IO interface?
This is the main point.
People like to run cdrecord -scanbus in order to find a list of usable devices. People like to see all SCSI devices in a single name space as they are all using the same protocol for communication.
A sane way to send SCSI commands to _any_ type of devices would be to have a SCSI generic transport layer that is independent from the high-level features of the OS and that is independent from whether there is a high-level driver for this device at all.
This is what I designed the scg driver interface for in 1986 and this is what Adaptec did in 1988 with ASPI. This is of course also why the SCSI standard commitee made a proposal for the CAM SCSI interface.
http://www.t10.org/ftp/t10/drafts/cam/cam-r12b.pdf http://www.t10.org/ftp/t10/drafts/cam3/cam3r03.pdf
Jörg
-- EMail:joerg@schily.isdn.cs.tu-berlin.de (home) Jörg Schilling D-13353 Berlin js@cs.tu-berlin.de (uni) schilling@fokus.fraunhofer.de (work) Blog: http://schily.blogspot.com/ URL: http://cdrecord.berlios.de/old/private/ ftp://ftp.berlios.de/pub/schily - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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