sd: Detect non-rotational devices

Detect non-rotational devices and set the queue flag accordingly.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 26 insertions, 0 deletions

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index a86064b6458..2148d659c28 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1795,6 +1795,29 @@ void sd_read_app_tag_own(struct scsi_disk *sdkp, unsigned char *buffer)
 }
 
 /**
+ * sd_read_block_characteristics - Query block dev. characteristics
+ * @disk: disk to query
+ */
+static void sd_read_block_characteristics(struct scsi_disk *sdkp)
+{
+        char *buffer;
+        u16 rot;
+
+        /* Block Device Characteristics VPD */
+        buffer = scsi_get_vpd_page(sdkp->device, 0xb1);
+
+        if (buffer == NULL)
+                return;
+
+        rot = get_unaligned_be16(&buffer[4]);
+
+        if (rot == 1)
+                queue_flag_set_unlocked(QUEUE_FLAG_NONROT, sdkp->disk->queue);
+
+        kfree(buffer);
+}
+
+/**
  *      sd_revalidate_disk - called the first time a new disk is seen,
  *      performs disk spin up, read_capacity, etc.
  *      @disk: struct gendisk we care about
@@ -1831,6 +1854,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
          */
         if (sdkp->media_present) {
                 sd_read_capacity(sdkp, buffer);
+                sd_read_block_characteristics(sdkp);
                 sd_read_write_protect_flag(sdkp, buffer);
                 sd_read_cache_type(sdkp, buffer);
                 sd_read_app_tag_own(sdkp, buffer);
@@ -1953,6 +1977,8 @@ static void sd_probe_async(void *data, async_cookie_t cookie)
         add_disk(gd);
         sd_dif_config_host(sdkp);
 
+        sd_revalidate_disk(gd);
+
         sd_printk(KERN_NOTICE, sdkp, "Attached SCSI %sdisk\n",
                   sdp->removable ? "removable " : "");
 }