From 0a0bcf9ed483728d0e174d3b5ac2104e69a9952f Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Thu, 27 Sep 2018 11:17:11 +1000
Subject: scsi: NCR5380: Check for bus reset

From: Finn Thain <fthain@telegraphics.com.au>

[ Upstream commit 6b0e87a6aafe12d75c2bea6fc8e49e88b98b3083 ]

The SR_RST bit isn't latched. Hence, detecting a bus reset isn't reliable.
When it is detected, the right thing to do is to drop all connected and
disconnected commands. The code for that is already present so refactor it and
call it when SR_RST is set.

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/scsi/NCR5380.c | 74 +++++++++++++++++++++++++-----------------
 1 file changed, 45 insertions(+), 29 deletions(-)

diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c
index bce6c990d060a..8ec68dcc0cc4a 100644
--- a/drivers/scsi/NCR5380.c
+++ b/drivers/scsi/NCR5380.c
@@ -131,6 +131,7 @@
 
 static int do_abort(struct Scsi_Host *);
 static void do_reset(struct Scsi_Host *);
+static void bus_reset_cleanup(struct Scsi_Host *);
 
 /**
  * initialize_SCp - init the scsi pointer field
@@ -885,7 +886,14 @@ static irqreturn_t __maybe_unused NCR5380_intr(int irq, void *dev_id)
 			/* Probably Bus Reset */
 			NCR5380_read(RESET_PARITY_INTERRUPT_REG);
 
-			dsprintk(NDEBUG_INTR, instance, "unknown interrupt\n");
+			if (sr & SR_RST) {
+				/* Certainly Bus Reset */
+				shost_printk(KERN_WARNING, instance,
+					     "bus reset interrupt\n");
+				bus_reset_cleanup(instance);
+			} else {
+				dsprintk(NDEBUG_INTR, instance, "unknown interrupt\n");
+			}
 #ifdef SUN3_SCSI_VME
 			dregs->csr |= CSR_DMA_ENABLE;
 #endif
@@ -2297,31 +2305,12 @@ out:
 }
 
 
-/**
- * NCR5380_host_reset - reset the SCSI host
- * @cmd: SCSI command undergoing EH
- *
- * Returns SUCCESS
- */
-
-static int NCR5380_host_reset(struct scsi_cmnd *cmd)
+static void bus_reset_cleanup(struct Scsi_Host *instance)
 {
-	struct Scsi_Host *instance = cmd->device->host;
 	struct NCR5380_hostdata *hostdata = shost_priv(instance);
 	int i;
-	unsigned long flags;
 	struct NCR5380_cmd *ncmd;
 
-	spin_lock_irqsave(&hostdata->lock, flags);
-
-#if (NDEBUG & NDEBUG_ANY)
-	shost_printk(KERN_INFO, instance, __func__);
-#endif
-	NCR5380_dprint(NDEBUG_ANY, instance);
-	NCR5380_dprint_phase(NDEBUG_ANY, instance);
-
-	do_reset(instance);
-
 	/* reset NCR registers */
 	NCR5380_write(MODE_REG, MR_BASE);
 	NCR5380_write(TARGET_COMMAND_REG, 0);
@@ -2333,14 +2322,6 @@ static int NCR5380_host_reset(struct scsi_cmnd *cmd)
 	 * commands!
 	 */
 
-	list_for_each_entry(ncmd, &hostdata->unissued, list) {
-		struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
-
-		cmd->result = DID_RESET << 16;
-		cmd->scsi_done(cmd);
-	}
-	INIT_LIST_HEAD(&hostdata->unissued);
-
 	if (hostdata->selecting) {
 		hostdata->selecting->result = DID_RESET << 16;
 		complete_cmd(instance, hostdata->selecting);
@@ -2374,6 +2355,41 @@ static int NCR5380_host_reset(struct scsi_cmnd *cmd)
 
 	queue_work(hostdata->work_q, &hostdata->main_task);
 	maybe_release_dma_irq(instance);
+}
+
+/**
+ * NCR5380_host_reset - reset the SCSI host
+ * @cmd: SCSI command undergoing EH
+ *
+ * Returns SUCCESS
+ */
+
+static int NCR5380_host_reset(struct scsi_cmnd *cmd)
+{
+	struct Scsi_Host *instance = cmd->device->host;
+	struct NCR5380_hostdata *hostdata = shost_priv(instance);
+	unsigned long flags;
+	struct NCR5380_cmd *ncmd;
+
+	spin_lock_irqsave(&hostdata->lock, flags);
+
+#if (NDEBUG & NDEBUG_ANY)
+	shost_printk(KERN_INFO, instance, __func__);
+#endif
+	NCR5380_dprint(NDEBUG_ANY, instance);
+	NCR5380_dprint_phase(NDEBUG_ANY, instance);
+
+	list_for_each_entry(ncmd, &hostdata->unissued, list) {
+		struct scsi_cmnd *scmd = NCR5380_to_scmd(ncmd);
+
+		scmd->result = DID_RESET << 16;
+		scmd->scsi_done(scmd);
+	}
+	INIT_LIST_HEAD(&hostdata->unissued);
+
+	do_reset(instance);
+	bus_reset_cleanup(instance);
+
 	spin_unlock_irqrestore(&hostdata->lock, flags);
 
 	return SUCCESS;
-- 
2.20.1