[SCSI] scsi_lib: fix recognition of cache type of Initio SBP-2 bridges

Regardless what mode page was asked for, Initio INIC-14x0 and
INIC-2430 always return page 6 without mode page headers.  Try to
recognise this as a special case in scsi_mode_sense and setting the
mode sense headers accordingly.

Signed-off-by: Al Viro <viro@ftp.linux.org.uk>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

2 files changed, 17 insertions, 2 deletions

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 1fe4fd83e305..eab303d148d8 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1892,8 +1892,16 @@ scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
         }
 
         if(scsi_status_is_good(result)) {
-                data->header_length = header_length;
-                if(use_10_for_ms) {
+                if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b &&
+                             (modepage == 6 || modepage == 8))) {
+                        /* Initio breakage? */
+                        header_length = 0;
+                        data->length = 13;
+                        data->medium_type = 0;
+                        data->device_specific = 0;
+                        data->longlba = 0;
+                        data->block_descriptor_length = 0;
+                } else if(use_10_for_ms) {
                         data->length = buffer[0]*256 + buffer[1] + 2;
                         data->medium_type = buffer[2];
                         data->device_specific = buffer[3];
@@ -1906,6 +1914,7 @@ scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
                         data->device_specific = buffer[2];
                         data->block_descriptor_length = buffer[3];
                 }
+                data->header_length = header_length;
         }
 
         return result;
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 76b4d14c0b3f..31c9685ebc5a 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1333,6 +1333,12 @@ sd_read_cache_type(struct scsi_disk *sdkp, char *diskname,
         if (!scsi_status_is_good(res))
                 goto bad_sense;
 
+        if (!data.header_length) {
+                modepage = 6;
+                printk(KERN_ERR "%s: missing header in MODE_SENSE response\n",
+                       diskname);
+        }
+
         /* that went OK, now ask for the proper length */
         len = data.length;