version 3.18.44 to 3.18.45 introduced a bug in "drivers/scsi/megaraid/megaraid_sas_base.c"

[Dashi DS1 Cao]

--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -1614,16 +1614,13 @@ megasas_queue_command(struct Scsi_Host *shost, struct scsi_cmnd *scmd)
                goto out_done;
        }

-       switch (scmd->cmnd[0]) {
-       case SYNCHRONIZE_CACHE:
-               /*
-                * FW takes care of flush cache on its own
-                * No need to send it down
-                */
+       /*
+        * FW takes care of flush cache on its own for Virtual Disk.
+        * No need to send it down for VD. For JBOD send SYNCHRONIZE_CACHE to FW.
+        */
+       if ((scmd->cmnd[0] == SYNCHRONIZE_CACHE) && MEGASAS_IS_LOGICAL(scmd)) {
                scmd->result = DID_OK << 16;
                goto out_done;
-       default:
-               break;
        }

        if (instance->instancet->build_and_issue_cmd(instance, scmd)) {

MEGASAS_IS_LOGICAL is defined to be a macro with '?' operator, which has a lower precedence than '&&'.
The macro should have been defined as:
--- a/drivers/scsi/megaraid/megaraid_sas.h
+++ b/drivers/scsi/megaraid/megaraid_sas.h
@@ -1823,7 +1823,7 @@ struct megasas_instance_template {
 };

 #define MEGASAS_IS_LOGICAL(scp)                                                \
-       (scp->device->channel < MEGASAS_MAX_PD_CHANNELS) ? 0 : 1
+       ((scp->device->channel < MEGASAS_MAX_PD_CHANNELS) ? 0 : 1)

 #define MEGASAS_DEV_INDEX(inst, scp)                                   \
        ((scp->device->channel % 2) * MEGASAS_MAX_DEV_PER_CHANNEL) +    \

Dashi Cao