Re: [PATCH 1/4] dpt_i2o: remove serial number usage

[Hannes Reinecke <hare@xxxxxxx>]

On 2/26/19 3:35 PM, Christoph Hellwig wrote:
> >   static u32 adpt_cmd_to_context(struct scsi_cmnd *cmd)
> >   {
> > -	return (u32)cmd->serial_number;
> > +	return (u32)cmd->request->tag + 1;
>
> Why the +1 (with the corresponding -1 later)?  Also why keep
> this rather confusing helper?
Because the original driver always checked for a non-zero serial number, 
and it might well be a firmware limitation (treating commands with a 
zero identifier as invalid commands).
So to keep the original behaviour I've added the '+ 1' to the tag number.

> >   }
> >   
> >   /*
> > @@ -604,28 +604,12 @@ static struct scsi_cmnd *
> >   	adpt_cmd_from_context(adpt_hba * pHba, u32 context)
> >   {
> >   	struct scsi_cmnd * cmd;
> >   
> >   	spin_unlock(pHba->host->host_lock);
> > +	cmd = scsi_host_find_tag(pHba->host, context - 1);
> >   	spin_lock(pHba->host->host_lock);
> >   
> > -	return NULL;
> > +	return cmd;
>
> No need to take the host_lock around scsi_host_find_tag.
> Also we cant probably drop this helper.
Okay, will be doing so.

Cheers,

Hannes