[SCSI] 3w-9xxx fix bug in sgl loading

This small patch fixes a bug in the 3w-9xxx driver where it would load
an invalid sgl address in the ioctl path even if request length was zero.

Signed-off-by: Adam Radford <aradford@gmail.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

1 files changed, 7 insertions, 4 deletions

diff --git a/drivers/scsi/3w-9xxx.c b/drivers/scsi/3w-9xxx.c
index 3bf75924741f..84d3bbaa95e7 100644
--- a/drivers/scsi/3w-9xxx.c
+++ b/drivers/scsi/3w-9xxx.c
@@ -76,6 +76,7 @@
                  Fix bug in twa_get_param() on 4GB+.
                  Use pci_resource_len() for ioremap().
    2.26.02.012 - Add power management support.
+   2.26.02.013 - Fix bug in twa_load_sgl().
 */
 
 #include <linux/module.h>
@@ -100,7 +101,7 @@
 #include "3w-9xxx.h"
 
 /* Globals */
-#define TW_DRIVER_VERSION "2.26.02.012"
+#define TW_DRIVER_VERSION "2.26.02.013"
 static TW_Device_Extension *twa_device_extension_list[TW_MAX_SLOT];
 static unsigned int twa_device_extension_count;
 static int twa_major = -1;
@@ -1382,10 +1383,12 @@ static void twa_load_sgl(TW_Device_Extension *tw_dev, TW_Command_Full *full_comm
                 newcommand = &full_command_packet->command.newcommand;
                 newcommand->request_id__lunl =
                         cpu_to_le16(TW_REQ_LUN_IN(TW_LUN_OUT(newcommand->request_id__lunl), request_id));
-                newcommand->sg_list[0].address = TW_CPU_TO_SGL(dma_handle + sizeof(TW_Ioctl_Buf_Apache) - 1);
-                newcommand->sg_list[0].length = cpu_to_le32(length);
+                if (length) {
+                        newcommand->sg_list[0].address = TW_CPU_TO_SGL(dma_handle + sizeof(TW_Ioctl_Buf_Apache) - 1);
+                        newcommand->sg_list[0].length = cpu_to_le32(length);
+                }
                 newcommand->sgl_entries__lunh =
-                        cpu_to_le16(TW_REQ_LUN_IN(TW_LUN_OUT(newcommand->sgl_entries__lunh), 1));
+                        cpu_to_le16(TW_REQ_LUN_IN(TW_LUN_OUT(newcommand->sgl_entries__lunh), length ? 1 : 0));
         } else {
                 oldcommand = &full_command_packet->command.oldcommand;
                 oldcommand->request_id = request_id;