Re: Re: inquiry in scsi_scan.c

[Matthew Dharm <mdharm-scsi@one-eyed-alien.net>]

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I'm told this is a bad idea because there are some HBA which snoop the
INQUIRY data.  Since I don't know how that snooping works, I can't comment
further.

Matt

On Mon, Jan 06, 2003 at 03:49:08PM -0500, Luben Tuikov wrote:
> Matthew Dharm wrote:
> > 
> > Perhaps the "best" fix here is to simply make scsi_scan.c only send 36 byte
> > inquiry requests if the bus is 'emulated'.  That would solve a world of
> > problems....
> 
> When scsi_scan.c does it's own scanning for SCSI Core, maybe it's best to
> ignore 36 < INQUIRY_DATA_LEN < 57, since this is just vendor specific
> data and SCSI Core is not interested in it.
> 
> In descriptive-C this looks like this:
> 
> </issue a 36 byte buffer INQUIRY/>
> </now dissect:/>
> 
> int bytes_got = max(bytes_requested - cmd->resid, 0);
> 
> if (31 < buffer[4] && buffer[4] < 52) {
> 	/* we don't care, do not issue another INQUIRY */	
> else if (buffer[4] >= 52) {
> 	bytes_requested = 5+buffer[4];
> 	/* issue another INQUIRY to get the additional flags, */
> 	/* plus any version descriptors if available */
> 	</insert code here/>
> 	bytes_got = max(bytes_requested - cmd->resid, 0);
> }
> 
> if (bytes_got != buffer[4]+5) {
> 	/* let's rely on the transport to have correctly set */
> 	/* cmd->resid and report a broken device server */
> 	</insert code here/>
> }
> 
> /* Now we rely on bytes_got */
> 
> </rest of scanning code/>
> 
> -- 
> Luben
> 

-- 
Matthew Dharm                              Home: mdharm-usb@one-eyed-alien.net 
Maintainer, Linux USB Mass Storage Driver

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					-- Greg
User Friendly, 5/11/1998

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