[SCSI] qla2xxx: fix for multiqueue in MISX disabled case

 Fix to accommodate a hardware bug in multiqueue mode that does not
 work properly when acknowledgement of MSIX Interrupts is disabled.

Signed-off-by: Anirban Chakraborty <anirban.chakraborty@qlogic.com>
Signed-off-by: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

4 files changed, 27 insertions, 2 deletions

diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h
index 7a81e988fffe..384afda7dbe9 100644
--- a/drivers/scsi/qla2xxx/qla_def.h
+++ b/drivers/scsi/qla2xxx/qla_def.h
@@ -2262,6 +2262,7 @@ struct qla_hw_data {
                 uint32_t        port0                   :1;
                 uint32_t        running_gold_fw         :1;
                 uint32_t        cpu_affinity_enabled    :1;
+                uint32_t        disable_msix_handshake  :1;
         } flags;
 
         /* This spinlock is used to protect "io transactions", you must
@@ -2384,6 +2385,7 @@ struct qla_hw_data {
 #define IS_QLA81XX(ha)          (IS_QLA8001(ha))
 #define IS_QLA2XXX_MIDTYPE(ha)  (IS_QLA24XX(ha) || IS_QLA84XX(ha) || \
                                 IS_QLA25XX(ha) || IS_QLA81XX(ha))
+#define IS_MSIX_NACK_CAPABLE(ha) (IS_QLA81XX(ha))
 #define IS_NOPOLLING_TYPE(ha)   ((IS_QLA25XX(ha) || IS_QLA81XX(ha)) && \
                                 (ha)->flags.msix_enabled)
 #define IS_FAC_REQUIRED(ha)     (IS_QLA81XX(ha))
diff --git a/drivers/scsi/qla2xxx/qla_init.c b/drivers/scsi/qla2xxx/qla_init.c
index b74924b279ef..73a793539d45 100644
--- a/drivers/scsi/qla2xxx/qla_init.c
+++ b/drivers/scsi/qla2xxx/qla_init.c
@@ -1442,7 +1442,17 @@ qla24xx_config_rings(struct scsi_qla_host *vha)
                         icb->firmware_options_2 |=
                                 __constant_cpu_to_le32(BIT_18);
 
-                icb->firmware_options_2 &= __constant_cpu_to_le32(~BIT_22);
+                /* Use Disable MSIX Handshake mode for capable adapters */
+                if (IS_MSIX_NACK_CAPABLE(ha)) {
+                        icb->firmware_options_2 &=
+                                __constant_cpu_to_le32(~BIT_22);
+                        ha->flags.disable_msix_handshake = 1;
+                        qla_printk(KERN_INFO, ha,
+                                "MSIX Handshake Disable Mode turned on\n");
+                } else {
+                        icb->firmware_options_2 |=
+                                __constant_cpu_to_le32(BIT_22);
+                }
                 icb->firmware_options_2 |= __constant_cpu_to_le32(BIT_23);
 
                 WRT_REG_DWORD(&reg->isp25mq.req_q_in, 0);
diff --git a/drivers/scsi/qla2xxx/qla_isr.c b/drivers/scsi/qla2xxx/qla_isr.c
index bc07d8392ac3..1692a883f4de 100644
--- a/drivers/scsi/qla2xxx/qla_isr.c
+++ b/drivers/scsi/qla2xxx/qla_isr.c
@@ -1928,7 +1928,7 @@ qla24xx_msix_rsp_q(int irq, void *dev_id)
 
         vha = qla25xx_get_host(rsp);
         qla24xx_process_response_queue(vha, rsp);
-        if (!ha->mqenable) {
+        if (!ha->flags.disable_msix_handshake) {
                 WRT_REG_DWORD(&reg->hccr, HCCRX_CLR_RISC_INT);
                 RD_REG_DWORD_RELAXED(&reg->hccr);
         }
@@ -1942,6 +1942,7 @@ qla25xx_msix_rsp_q(int irq, void *dev_id)
 {
         struct qla_hw_data *ha;
         struct rsp_que *rsp;
+        struct device_reg_24xx __iomem *reg;
 
         rsp = (struct rsp_que *) dev_id;
         if (!rsp) {
@@ -1951,6 +1952,14 @@ qla25xx_msix_rsp_q(int irq, void *dev_id)
         }
         ha = rsp->hw;
 
+        /* Clear the interrupt, if enabled, for this response queue */
+        if (rsp->options & ~BIT_6) {
+                reg = &ha->iobase->isp24;
+                spin_lock_irq(&ha->hardware_lock);
+                WRT_REG_DWORD(&reg->hccr, HCCRX_CLR_RISC_INT);
+                RD_REG_DWORD_RELAXED(&reg->hccr);
+                spin_unlock_irq(&ha->hardware_lock);
+        }
         queue_work_on((int) (rsp->id - 1), ha->wq, &rsp->q_work);
 
         return IRQ_HANDLED;
diff --git a/drivers/scsi/qla2xxx/qla_mid.c b/drivers/scsi/qla2xxx/qla_mid.c
index a47d34308a3a..2a4c7f4e7b69 100644
--- a/drivers/scsi/qla2xxx/qla_mid.c
+++ b/drivers/scsi/qla2xxx/qla_mid.c
@@ -696,6 +696,10 @@ qla25xx_create_rsp_que(struct qla_hw_data *ha, uint16_t options,
         /* Use alternate PCI devfn */
         if (LSB(rsp->rid))
                 options |= BIT_5;
+        /* Enable MSIX handshake mode on for uncapable adapters */
+        if (!IS_MSIX_NACK_CAPABLE(ha))
+                options |= BIT_6;
+
         rsp->options = options;
         rsp->id = que_id;
         reg = ISP_QUE_REG(ha, que_id);