4403 mpt_sas panic when pulling a drive

@@ -2019,10 +2019,11 @@
 static int
 mptsas_alloc_handshake_msg(mptsas_t *mpt, size_t alloc_size)
 {
         ddi_dma_attr_t  task_dma_attrs;
 
+        mpt->m_hshk_dma_size = 0;
         task_dma_attrs = mpt->m_msg_dma_attr;
         task_dma_attrs.dma_attr_sgllen = 1;
         task_dma_attrs.dma_attr_granular = (uint32_t)(alloc_size);
 
         /* allocate Task Management ddi_dma resources */

@@ -2037,10 +2038,12 @@
 }
 
 static void
 mptsas_free_handshake_msg(mptsas_t *mpt)
 {
+        if (mpt->m_hshk_dma_size == 0)
+                return;
         mptsas_dma_addr_destroy(&mpt->m_hshk_dma_hdl, &mpt->m_hshk_acc_hdl);
         mpt->m_hshk_dma_size = 0;
 }
 
 static int

@@ -15442,28 +15445,25 @@
         if (cookiep == NULL)
                 cookiep = &new_cookie;
 
         if (ddi_dma_alloc_handle(mpt->m_dip, &dma_attr, DDI_DMA_SLEEP,
             NULL, dma_hdp) != DDI_SUCCESS) {
-                dma_hdp = NULL;
                 return (FALSE);
         }
 
         if (ddi_dma_mem_alloc(*dma_hdp, alloc_size, &mpt->m_dev_acc_attr,
             DDI_DMA_CONSISTENT, DDI_DMA_SLEEP, NULL, dma_memp, &alloc_len,
             acc_hdp) != DDI_SUCCESS) {
                 ddi_dma_free_handle(dma_hdp);
-                dma_hdp = NULL;
                 return (FALSE);
         }
 
         if (ddi_dma_addr_bind_handle(*dma_hdp, NULL, *dma_memp, alloc_len,
             (DDI_DMA_RDWR | DDI_DMA_CONSISTENT), DDI_DMA_SLEEP, NULL,
             cookiep, &ncookie) != DDI_DMA_MAPPED) {
                 (void) ddi_dma_mem_free(acc_hdp);
                 ddi_dma_free_handle(dma_hdp);
-                dma_hdp = NULL;
                 return (FALSE);
         }
 
         return (TRUE);
 }

@@ -15475,7 +15475,6 @@
                 return;
 
         (void) ddi_dma_unbind_handle(*dma_hdp);
         (void) ddi_dma_mem_free(acc_hdp);
         ddi_dma_free_handle(dma_hdp);
-        dma_hdp = NULL;
 }