[PATCH 4.9 139/222] scsi: NCR5380: Handle BUS FREE during reselection

[Greg Kroah-Hartman]

From: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>

[ Upstream commit ca694afad707cb3ae2fdef3b28454444d9ac726e ]

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@xxxxxxxxx>
Signed-off-by: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/scsi/NCR5380.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c
index 03f9ddbc37fbb..27270631c70c2 100644
--- a/drivers/scsi/NCR5380.c
+++ b/drivers/scsi/NCR5380.c
@@ -2133,6 +2133,9 @@ static void NCR5380_reselect(struct Scsi_Host *instance)
 
 	if (NCR5380_poll_politely(instance,
 	                          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;
-- 
2.20.1