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List:       linux-scsi
Subject:    [PATCH] bnx2fc: Handle scope bits when array returns BUSY or TASK_SET_FULL
From:       Laurence Oberman <loberman () redhat ! com>
Date:       2019-09-09 12:05:56
Message-ID: 1568030756-17428-1-git-send-email-loberman () redhat ! com
[Download RAW message or body]

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);
-- 
1.8.3.1

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