RE: [EXT] [PATCH RFC v2 2/5] ufs: Use reserved tags for TMFs

["Bean Huo (beanhuo)" <beanhuo@micron.com>]

> 
> On 11/5/19 3:58 AM, Bean Huo (beanhuo) wrote:
> >>   	host = cmd->device->host;
> >>   	hba = shost_priv(host);
> >> -	tag = cmd->request->tag;
> >> +	tag = cmd->request->tag - hba->nutmrs;
> >> +	WARN_ON_ONCE(!ufshcd_valid_tag(hba, tag));
> >
> > Changing request tag number here is not proper way, we have trace tool
> > using this tag to track request from block, SCSI to UFS layer. If tags being
> changed in UFS driver, there will be a confusion.
> 
> Hi Bean,
> 
> Thanks for having taken a look. Which information is used by the tracing tool?
> cmd->request->tag or the variable called 'tag' above? The latter should not be
> modified by this patch. cmd->request->tag is modified however for every
> command that is not a TMF. Preserving the block layer tag value is possible but
> would require to introduce a new tag set for TMFs.
> 
> Thanks,
> 
> Bart.

Hi, Bart

We are using latter variable 'tag'.  
What I concern is that cmd->request->tag and variable tag(UFS driver uses this variable tag)
are consistent without this patch, and now we should change our tag tracking handling mechanism.
But it is not big deal, we can plus hba->nutmrs subtracted before  in order to in line with block/scsi tag. 

Thanks,

//Bean