Re: [PATCH 5/4] scsi: remove MSG_*_TAG defines

[Christoph Hellwig <hch@infradead.org>]

On Fri, Nov 28, 2014 at 10:58:58AM +0100, Bart Van Assche wrote:
> >  	if (disable_syn_offset_one_fix) {
> >-		scsiq->q2.tag_code &= ~MSG_SIMPLE_TAG;
> >+		scsiq->q2.tag_code &= ~SIMPLE_QUEUE_TAG;
> >  		scsiq->q2.tag_code |= (ASC_TAG_FLAG_DISABLE_ASYN_USE_SYN_FIX |
> >  				       ASC_TAG_FLAG_DISABLE_DISCONNECT);
> >  	} else {
> 
> One of the statements in advansys.c (tag_code &= 0xDC) makes assumptions
> about the numeric value of MSG_SIMPLE_TAG. This makes me wonder whether it
> is safe to change MSG_SIMPLE_TAG into another value ?

MSG_SIMPLE_TAG and SIMPLE_QUEUE_TAG are two different symbolic names
for the 0x20 value assigned to the SCSI-2 protocol "SIMPLE QUEUE TAG"
message.  Having both is confusing, so I decided to only keep the one
that is named closer to the spec, and in the same namespace as the
symbolic names we use for other SCSI-2 messages.