commit 7957ee71c7733ca20178a49ba7de2b84bbc53d29
author Hannes Reinecke <hare@suse.de> Wed Oct 29 13:00:16 2014 +0100
committer Paolo Bonzini <pbonzini@redhat.com> Fri Oct 31 11:29:01 2014 +0100
tree 7df6815d4e019f35d00e29a48f55d6446470d0fb
parent 6df5718bd3ec56225c44cf96440c723c1b611b87

megasas: Fixup MSI-X handling

MSI-X works slightly different than INTx; the doorbell
registers are not necessarily used as MSI-X interrupts
are directed anyway. So the head pointer on the
reply queue needs to be updated as soon as a frame
is completed, and we can set the doorbell only
when in INTx mode.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

hw/scsi/megasas.c

diff --git a/hw/scsi/megasas.c b/hw/scsi/megasas.c
index c0d8215..604252a 100644
--- a/hw/scsi/megasas.c
+++ b/hw/scsi/megasas.c
@@ -545,34 +545,41 @@
          * Context is opaque, but emulation is running in
          * little endian. So convert it.
          */
-        tail = s->reply_queue_head;
         if (megasas_use_queue64(s)) {
-            queue_offset = tail * sizeof(uint64_t);
+            queue_offset = s->reply_queue_head * sizeof(uint64_t);
             stq_le_phys(&address_space_memory,
                         s->reply_queue_pa + queue_offset, context);
         } else {
-            queue_offset = tail * sizeof(uint32_t);
+            queue_offset = s->reply_queue_head * sizeof(uint32_t);
             stl_le_phys(&address_space_memory,
                         s->reply_queue_pa + queue_offset, context);
         }
-        s->reply_queue_head = megasas_next_index(s, tail, s->fw_cmds);
         s->reply_queue_tail = ldl_le_phys(&address_space_memory,
                                           s->consumer_pa);
         trace_megasas_qf_complete(context, s->reply_queue_head,
-                                  s->reply_queue_tail, s->busy, s->doorbell);
+                                  s->reply_queue_tail, s->busy);
     }
 
     if (megasas_intr_enabled(s)) {
+        /* Update reply queue pointer */
+        s->reply_queue_tail = ldl_le_phys(&address_space_memory,
+                                          s->consumer_pa);
+        tail = s->reply_queue_head;
+        s->reply_queue_head = megasas_next_index(s, tail, s->fw_cmds);
+        trace_megasas_qf_update(s->reply_queue_head, s->reply_queue_tail,
+                                s->busy);
+        stl_le_phys(&address_space_memory,
+                    s->producer_pa, s->reply_queue_head);
         /* Notify HBA */
-        s->doorbell++;
-        if (s->doorbell == 1) {
-            if (msix_enabled(pci_dev)) {
-                trace_megasas_msix_raise(0);
-                msix_notify(pci_dev, 0);
-            } else if (msi_enabled(pci_dev)) {
-                trace_megasas_msi_raise(0);
-                msi_notify(pci_dev, 0);
-            } else {
+        if (msix_enabled(pci_dev)) {
+            trace_megasas_msix_raise(0);
+            msix_notify(pci_dev, 0);
+        } else if (msi_enabled(pci_dev)) {
+            trace_megasas_msi_raise(0);
+            msi_notify(pci_dev, 0);
+        } else {
+            s->doorbell++;
+            if (s->doorbell == 1) {
                 trace_megasas_irq_raise();
                 pci_irq_assert(pci_dev);
             }
@@ -2028,7 +2035,7 @@
         trace_megasas_mmio_readl("MFI_OMSK", retval);
         break;
     case MFI_ODCR0:
-        retval = s->doorbell;
+        retval = s->doorbell ? 1 : 0;
         trace_megasas_mmio_readl("MFI_ODCR0", retval);
         break;
     case MFI_DIAG:
@@ -2103,15 +2110,8 @@
     case MFI_ODCR0:
         trace_megasas_mmio_writel("MFI_ODCR0", val);
         s->doorbell = 0;
-        if (s->producer_pa && megasas_intr_enabled(s)) {
-            /* Update reply queue pointer */
-            s->reply_queue_tail = ldl_le_phys(&address_space_memory,
-                                              s->consumer_pa);
-            trace_megasas_qf_update(s->reply_queue_head, s->reply_queue_tail,
-                                    s->busy);
-            stl_le_phys(&address_space_memory,
-                        s->producer_pa, s->reply_queue_head);
-            if (!msix_enabled(pci_dev)) {
+        if (megasas_intr_enabled(s)) {
+            if (!msix_enabled(pci_dev) && !msi_enabled(pci_dev)) {
                 trace_megasas_irq_lower();
                 pci_irq_deassert(pci_dev);
             }