commit f3ddac1918fe963bcbf8d407a3a3c0881b47248b
author Chad Dupuis <chad.dupuis@qlogic.com> Wed Oct 30 03:38:16 2013 -0400
committer James Bottomley <JBottomley@Parallels.com> Thu Dec 19 07:38:58 2013 -0800
tree 307e736319180d8930154ce40309f017e3696673
parent fe1b806f4f7172b1eae18ddeebb7d8fb351043f7

[SCSI] qla2xxx: Disable adapter when we encounter a PCI disconnect.

If we become disconnected from the PCI bus/PCIe fabric, there can be long delays
in register reads which can cause erroneous decisions to be made and cause a
soft lockup if a lock is held too long. As a preventative measure, check for a
disconnection (register reads that return -1) and then disable the board if we
find ourselves in this condition. For now, check in our interrupt handlers and
the per adapter one second timer.

Signed-off-by: Chad Dupuis <chad.dupuis@qlogic.com>
Signed-off-by: Saurav Kashyap <saurav.kashyap@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

drivers/scsi/qla2xxx/qla_nx.c

diff --git a/drivers/scsi/qla2xxx/qla_nx.c b/drivers/scsi/qla2xxx/qla_nx.c
index 11ce53d..3da2372 100644
--- a/drivers/scsi/qla2xxx/qla_nx.c
+++ b/drivers/scsi/qla2xxx/qla_nx.c
@@ -2096,6 +2096,7 @@
 	int status = 0;
 	unsigned long flags;
 	uint32_t stat = 0;
+	uint32_t host_int = 0;
 	uint16_t mb[4];
 
 	rsp = (struct rsp_que *) dev_id;
@@ -2111,7 +2112,10 @@
 	spin_lock_irqsave(&ha->hardware_lock, flags);
 	vha = pci_get_drvdata(ha->pdev);
 	do {
-		if (RD_REG_DWORD(&reg->host_int)) {
+		host_int = RD_REG_DWORD(&reg->host_int);
+		if (qla2x00_check_reg_for_disconnect(vha, host_int))
+			break;
+		if (host_int) {
 			stat = RD_REG_DWORD(&reg->host_status);
 
 			switch (stat & 0xff) {
@@ -2156,6 +2160,7 @@
 	struct rsp_que *rsp;
 	struct device_reg_82xx __iomem *reg;
 	unsigned long flags;
+	uint32_t host_int = 0;
 
 	rsp = (struct rsp_que *) dev_id;
 	if (!rsp) {
@@ -2168,8 +2173,12 @@
 	reg = &ha->iobase->isp82;
 	spin_lock_irqsave(&ha->hardware_lock, flags);
 	vha = pci_get_drvdata(ha->pdev);
+	host_int = RD_REG_DWORD(&reg->host_int);
+	if (qla2x00_check_reg_for_disconnect(vha, host_int))
+		goto out;
 	qla24xx_process_response_queue(vha, rsp);
 	WRT_REG_DWORD(&reg->host_int, 0);
+out:
 	spin_unlock_irqrestore(&ha->hardware_lock, flags);
 	return IRQ_HANDLED;
 }
@@ -2183,6 +2192,7 @@
 	struct device_reg_82xx __iomem *reg;
 	int status = 0;
 	uint32_t stat;
+	uint32_t host_int = 0;
 	uint16_t mb[4];
 	unsigned long flags;
 
@@ -2198,7 +2208,10 @@
 	spin_lock_irqsave(&ha->hardware_lock, flags);
 	vha = pci_get_drvdata(ha->pdev);
 
-	if (RD_REG_DWORD(&reg->host_int)) {
+	host_int = RD_REG_DWORD(&reg->host_int);
+	if (qla2x00_check_reg_for_disconnect(vha, host_int))
+		goto out;
+	if (host_int) {
 		stat = RD_REG_DWORD(&reg->host_status);
 		switch (stat & 0xff) {
 		case 0x1:
@@ -2226,6 +2239,7 @@
 		}
 	}
 	WRT_REG_DWORD(&reg->host_int, 0);
+out:
 	spin_unlock_irqrestore(&ha->hardware_lock, flags);
 }