From: Finn Thain <fthain@telegraphics.com.au>
Date: Thu, 27 Sep 2018 11:17:11 +1000
Subject: scsi: NCR5380: Handle BUS FREE during reselection
Git-commit: ca694afad707cb3ae2fdef3b28454444d9ac726e
Patch-mainline: v4.20-rc1
References: git-fixes

The X3T9.2 specification (draft) says, under "6.1.4.2 RESELECTION time-out
procedure", that a target may assert RST or go to BUS FREE phase if the
initiator does not respond within 200 us. Something like this has been
observed with AztecMonster II target. When it happens, all we can do is wait
for the target to try again.

Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Lee Duncan <lduncan@suse.com>
---
 drivers/scsi/NCR5380.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c
index 419033643015..b9a3eb0647e4 100644
--- a/drivers/scsi/NCR5380.c
+++ b/drivers/scsi/NCR5380.c
@@ -2047,6 +2047,9 @@ static void NCR5380_reselect(struct Scsi_Host *instance)
 
 	if (NCR5380_poll_politely(hostdata,
 	                          STATUS_REG, SR_REQ, SR_REQ, 2 * HZ) < 0) {
+		if ((NCR5380_read(STATUS_REG) & (SR_BSY | SR_SEL)) == 0)
+			/* BUS FREE phase */
+			return;
 		shost_printk(KERN_ERR, instance, "reselect: REQ timeout\n");
 		do_abort(instance);
 		return;