From: Tomas Henzl <thenzl@redhat.com>
Date: Sun, 29 Aug 2010 15:49:45 -0400
Subject: [block] cciss: detect bad alignment
Message-id: <1283097002-3341-47-git-send-email-thenzl@redhat.com>
Patchwork-id: 27878
O-Subject: [RHEL6 PATCH 46/63] cciss: detect bad alignment
Bugzilla: 568830
RH-Acked-by: Neil Horman <nhorman@redhat.com>

detect bad alignment during compile

diff --git a/drivers/block/cciss_scsi.c b/drivers/block/cciss_scsi.c
index 51b5096..dde65a1 100644
--- a/drivers/block/cciss_scsi.c
+++ b/drivers/block/cciss_scsi.c
@@ -203,9 +203,11 @@ scsi_cmd_stack_setup(int ctlr, struct cciss_scsi_adapter_data_t *sa)
 	stk = &sa->cmd_stack; 
 	size = sizeof(struct cciss_scsi_cmd_stack_elem_t) * CMD_STACK_SIZE;
 
-	// pci_alloc_consistent guarantees 32-bit DMA address will
-	// be used
-
+	/* Check alignment, see cciss_cmd.h near CommandList_struct def. */
+	BUILD_BUG_ON((sizeof(struct cciss_scsi_cmd_stack_elem_t) % 8) != 0);
+	/* pci_alloc_consistent guarantees 32-bit DMA address will
+	 * be used
+	 */
 	stk->pool = (struct cciss_scsi_cmd_stack_elem_t *)
 		pci_alloc_consistent(hba[ctlr]->pdev, size, &stk->cmd_pool_handle);