Re: [linux-usb-devel] Re: inquiry in scsi_scan.c

[Luben Tuikov <luben@splentec.com>]

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