Indeed, my copy of the SCSI 3 SPC-1 (ftp://ftp.t10.org/t10/drafts/spc/spc-r11a.pdf dated 21-Mar-1997) and SPC-2 (ftp://ftp.t10.org/t10/drafts/spc2/spc2r18.pdf dated 21-May-2000) show them differently. SPC-3 isn't available for download. Anyone have the "final" copy (if indeed it's not still in draft state)? SCSI1 - byte 1 bits 5-7 are the LUN address SCSI2 - byte 1 bits 5-7 are the LUN address SCSI3 SPC-1 - byte 1 bits 5-7 are marked "reserved" for all commands SCSI3 SPC-2 - byte 1 bits 5-7 are now used for self test codes for the SEND DIAGNOSTIC command, "reserved" for all other commands that I could see. Maybe the proper logic would be to switch ioctl_send_command() functions based on the version field in the INQUIRY data as you suggest, and then in the SCSI3 case, handle SEND_DIAGNOSTIC separately? I hereby retract my patch until a better solution is agreed upon that doesn't break SCSI backward compatability. Thanks, Matt -----Original Message----- From: Guest section DW [mailto:[EMAIL PROTECTED]] Sent: Monday, September 18, 2000 3:57 PM To: [EMAIL PROTECTED]; [EMAIL PROTECTED]; [EMAIL PROTECTED]; [EMAIL PROTECTED]; [EMAIL PROTECTED]; [EMAIL PROTECTED]; [EMAIL PROTECTED] Cc: [EMAIL PROTECTED] Subject: Re: [PATCH] scsi_ioctl_send_command() shouldn't write SEND DIAGNOSTIC S reserved bits On Mon, Sep 18, 2000 at 11:31:09AM -0500, [EMAIL PROTECTED] wrote: > This patch prevents scsi_ioctl_send_command() from overwriting the SEND > DIAGNOSTICS (Drive Self Test) reserved bits in cmd[1], as found in SCSI-3. > Code provided by Michael Landrus of Dell. > > Comments are requested. If there are no objections, Linus and Alan please > apply. > Below are patches to kernels 2.2.18-pre8 and 2.4.0-test9-pre1. > - cmd[1] = ( cmd[1] & 0x1f ) | (dev->lun << 5); > + if ( cmd[0] != 0x1d ) // don't overwrite the SCSI-3 SEND DIAGNOSTICS > reserved bits > + cmd[1] = (cmd[1] & 0x1f) | (dev->lun << 5); I am a bit surprised: why only SEND DIAGNOSTICS? If I am not mistaken SCSI-1 used this 3-bit LUN field in all commands, and SCSI-2 still does, but the standard says: ---------------------------------------------------------------------------- 7.2.2 Logical unit number ... NOTICE: The logical unit number field is included in the command descriptor block for compatibility with some SCSI-1 devices. This field may be reclaimed in SCSI-3. ---------------------------------------------------------------------------- and SCSI-3 calls these bits "reserved", for all commands, also for SEND DIAGNOSTICS. So: (i) I don't see what is special with SEND DIAGNOSTICS. Maybe for SCSI-3 the lun should never be inserted. (ii) On the other hand, for SCSI-1 the lun should always be inserted. Once these bits really get used again (are there already examples of a new use?) I suppose we should introduce a new SCSI3_IOCTL_SEND_COMMAND instead of changing SCSI_IOCTL_SEND_COMMAND. Andries - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
