RE: [PATCH 1/4] [SCSI]stex: fix id mapping issue

[Ed Lin]

> -----Original Message-----
> From: James Bottomley [mailto:James.Bottomley@xxxxxxxxxxxx] 
> Sent: Saturday, March 31, 2007 7:22 AM
> To: Ed Lin
> Cc: linux-scsi; linux-kernel; jeff; Promise_Linux
> Subject: Re: [PATCH 1/4] [SCSI]stex: fix id mapping issue
> 
> 
> On Fri, 2007-03-30 at 15:21 -0700, Ed Lin wrote:
> > The internal id/lun mapping of st_vsc and st_vsc1 
> controllers is different
> > from st_shasta. The original driver code can only  map 
> first 16 'entities'
> > for st_vsc and st_vsc1 while there are actually 128 available.
> > 
> > Also the  ST_MAX_LUN_PER_TARGET should be 8, although this can do
> > no harm because inquiries beyond boundary are discarded by firmware.
> > 
> > The correct internal mapping should be:
> > id:0~15, lun:0~7 (st_shasta)
> > id:0, lun:0~127 (st_yosemite)
> > id:0~127, lun:0 (st_vsc and st_vsc1)
> > To scsi mid layer they are all channel:0~7, id:0~15, lun:0, 
> with a maximun
> > 'entity' number of 128. The RAID console only interfaces to 
> scsi mid layer
> > and is always mapped at channel:0, id:16, lun:0.
> 
> I'm with Christoph here ... if we're going to break the backwards
> compatibility of the mappings (which your code does) then we 
> could just
> dump channel and use the SCSI id and lun directly.
> 
> Understanding this code is predicated on this quirky definition in
> stex_queuecommand:
> 
> 	id = cmd->device->id;
> 	lun = cmd->device->channel; /* firmware lun issue work around */
>                            ^^^^^^^
> 
> > @ -645,12 +645,16 @@ stex_queuecommand(struct scsi_cmnd *cmd,
> >  
> >  	req = stex_alloc_req(hba);
> >  
> > -	if (hba->cardtype == st_yosemite) {
> > -		req->lun = lun * (ST_MAX_TARGET_NUM - 1) + id;
> 
> This looks to be correct, it goes up id 0 to ST_MAX_TARGET_NUM -1 then
> takes the next channel.
> 
> > -		req->target = 0;
> > -	} else {
> > +	if (hba->cardtype == st_shasta) {
> >  		req->lun = lun;
> >  		req->target = id;
> > +	} else if (hba->cardtype == st_yosemite){
> > +		req->lun = id * ST_MAX_LUN_PER_TARGET + lun;
> > +		req->target = 0;
> > +	} else {
> > +		/* st_vsc and st_vsc1 */
> > +		req->lun = 0;
> > +		req->target = id * ST_MAX_LUN_PER_TARGET + lun;
> 
> These both look to be wrong.  You're taking the channel as the lowest
> common denominator, so your first target is on channel 1 id 
> 0, your next
> on channel 2, id 0 and so on.  That's really going to mess with the
> ordering (which will be user visible) is that really what you want?
> 

How about the attached one?

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