On Tue, Feb 26, 2019 at 03:39:54PM +0100, Hannes Reinecke wrote: > 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. Please add a comment explaining this then.