commit 364398324c901bc834f762eb5443d2e5a1d2a0db
author gurinder.shergill@hp.com <gurinder.shergill@hp.com> Tue Apr 23 10:13:17 2013 -0700
committer James Bottomley <JBottomley@Parallels.com> Sun May 12 12:51:15 2013 -0700
tree 9041d31c3d28f2a77cc9e65e131134a5c9a904f5
parent f722406faae2d073cc1d01063d1123c35425939e

[SCSI] qla2xxx: Fix for locking issue between driver ISR and mailbox routines

The driver uses ha->mbx_cmd_flags variable to pass information between
its ISR and mailbox routines, however, it does so without the protection of
any locks.  Under certain conditions, this can lead to multiple mailbox
command completions being signaled, which, in turn, leads to a false
mailbox timeout error for the subsequently issued mailbox command.

The issue occurs frequently but intermittenly with the Qlogic 8GFC mezz
card during card initialization, resulting in card initialization failure.

Signed-off-by: Gurinder (Sunny) Shergill <gurinder.shergill@hp.com>
Acked-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 10754f51..cce0cd0 100644
--- a/drivers/scsi/qla2xxx/qla_nx.c
+++ b/drivers/scsi/qla2xxx/qla_nx.c
@@ -2074,9 +2074,6 @@
 		}
 		WRT_REG_DWORD(&reg->host_int, 0);
 	}
-	spin_unlock_irqrestore(&ha->hardware_lock, flags);
-	if (!ha->flags.msi_enabled)
-		qla82xx_wr_32(ha, ha->nx_legacy_intr.tgt_mask_reg, 0xfbff);
 
 #ifdef QL_DEBUG_LEVEL_17
 	if (!irq && ha->flags.eeh_busy)
@@ -2085,11 +2082,12 @@
 		    status, ha->mbx_cmd_flags, ha->flags.mbox_int, stat);
 #endif
 
-	if (test_bit(MBX_INTR_WAIT, &ha->mbx_cmd_flags) &&
-	    (status & MBX_INTERRUPT) && ha->flags.mbox_int) {
-		set_bit(MBX_INTERRUPT, &ha->mbx_cmd_flags);
-		complete(&ha->mbx_intr_comp);
-	}
+	qla2x00_handle_mbx_completion(ha, status);
+	spin_unlock_irqrestore(&ha->hardware_lock, flags);
+
+	if (!ha->flags.msi_enabled)
+		qla82xx_wr_32(ha, ha->nx_legacy_intr.tgt_mask_reg, 0xfbff);
+
 	return IRQ_HANDLED;
 }
 
@@ -2149,8 +2147,6 @@
 		WRT_REG_DWORD(&reg->host_int, 0);
 	} while (0);
 
-	spin_unlock_irqrestore(&ha->hardware_lock, flags);
-
 #ifdef QL_DEBUG_LEVEL_17
 	if (!irq && ha->flags.eeh_busy)
 		ql_log(ql_log_warn, vha, 0x5044,
@@ -2158,11 +2154,9 @@
 		    status, ha->mbx_cmd_flags, ha->flags.mbox_int, stat);
 #endif
 
-	if (test_bit(MBX_INTR_WAIT, &ha->mbx_cmd_flags) &&
-		(status & MBX_INTERRUPT) && ha->flags.mbox_int) {
-			set_bit(MBX_INTERRUPT, &ha->mbx_cmd_flags);
-			complete(&ha->mbx_intr_comp);
-	}
+	qla2x00_handle_mbx_completion(ha, status);
+	spin_unlock_irqrestore(&ha->hardware_lock, flags);
+
 	return IRQ_HANDLED;
 }
 
@@ -3345,7 +3339,7 @@
 		ha->flags.mbox_busy = 0;
 		ql_log(ql_log_warn, vha, 0x6010,
 		    "Doing premature completion of mbx command.\n");
-		if (test_bit(MBX_INTR_WAIT, &ha->mbx_cmd_flags))
+		if (test_and_clear_bit(MBX_INTR_WAIT, &ha->mbx_cmd_flags))
 			complete(&ha->mbx_intr_comp);
 	}
 }