Re: [PATCH] bnx2fc: Handle scope bits when array returns BUSY or TASK_SET_FULL

[cdupuis1@gmail.com]

On Mon, 2019-09-09 at 08:05 -0400, Laurence Oberman wrote:
> The qla2xxx driver had this issue as well when the newer array
> firmware returned the retry_delay_timer in the fcp_rsp.
> The bnx2fc is not handling the masking of the scope bits either
> so the retry_delay_timestamp value lands up being a large value
> added to the timer timestamp delaying I/O for up to 27 Minutes.
> This patch adds similar code to handle this to the
> bnx2fc driver to avoid the huge delay.
> 
> V2. Indent comments as suggested
> 
> Signed-off-by: Laurence Oberman <loberman@redhat.com>
> ---
>  drivers/scsi/bnx2fc/bnx2fc_io.c | 23 ++++++++++++++++++++---
>  1 file changed, 20 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/scsi/bnx2fc/bnx2fc_io.c
> b/drivers/scsi/bnx2fc/bnx2fc_io.c
> index 9e50e5b..39f4aeb 100644
> --- a/drivers/scsi/bnx2fc/bnx2fc_io.c
> +++ b/drivers/scsi/bnx2fc/bnx2fc_io.c
> @@ -1928,6 +1928,7 @@ void bnx2fc_process_scsi_cmd_compl(struct
> bnx2fc_cmd *io_req,
>  	struct bnx2fc_rport *tgt = io_req->tgt;
>  	struct scsi_cmnd *sc_cmd;
>  	struct Scsi_Host *host;
> +	u16 scope, qualifier = 0;
>  
>  
>  	/* scsi_cmd_cmpl is called with tgt lock held */
> @@ -1997,12 +1998,28 @@ void bnx2fc_process_scsi_cmd_compl(struct
> bnx2fc_cmd *io_req,
>  
>  			if (io_req->cdb_status ==
> SAM_STAT_TASK_SET_FULL ||
>  			    io_req->cdb_status == SAM_STAT_BUSY) {
> +				/* Newer array firmware with BUSY or
> +				 * TASK_SET_FULL may return a status
> that needs
> +				 * the scope bits masked.
> +				 * Or a huge delay timestamp up to 27
> minutes
> +				 * can result.
> +				*/
> +				if (fcp_rsp->retry_delay_timer) {
> +					/* Upper 2 bits */
> +					scope = fcp_rsp-
> >retry_delay_timer
> +						& 0xC000;
> +					/* Lower 14 bits */
> +					qualifier = fcp_rsp-
> >retry_delay_timer
> +						& 0x3FFF;
> +				}
> +				if (scope > 0 && qualifier > 0 &&
> +					qualifier <= 0x3FEF) {
>  					/* Set the jiffies + 
> 					retry_delay_timer * 100ms
>  				   	for the rport/tgt 
> 					*/
> -				tgt->retry_delay_timestamp = jiffies +
> -					fcp_rsp->retry_delay_timer * HZ
> / 10;
> +					tgt->retry_delay_timestamp =
> jiffies +
> +						(qualifier * HZ / 10);
> +				}
>  			}
> -
>  		}
>  		if (io_req->fcp_resid)
>  			scsi_set_resid(sc_cmd, io_req->fcp_resid);

V2 looks good.

Reviewed-by: Chad Dupuis <cdupuis1@gmail.com>