Query the block limits VPD page and adjust queue minimum and optimal I/O
sizes.
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
---
drivers/scsi/sd.c | 24 ++++++++++++++++++++++++
1 files changed, 24 insertions(+), 0 deletions(-)
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 2f3a78e..d4eb5a4 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_limits - Query disk device for preferred I/O sizes.
+ * @disk: disk to query
+ */
+static void sd_read_block_limits(struct scsi_disk *sdkp)
+{
+ unsigned int sector_sz = sdkp->device->sector_size;
+ char *buffer;
+
+ /* Block Limits VPD */
+ buffer = scsi_get_vpd_page(sdkp->device, 0xb0);
+
+ if (buffer == NULL)
+ return;
+
+ blk_queue_io_min(sdkp->disk->queue,
+ get_unaligned_be16(&buffer[6]) * sector_sz);
+ blk_queue_io_opt(sdkp->disk->queue,
+ get_unaligned_be32(&buffer[12]) * sector_sz);
+
+ kfree(buffer);
+}
+
+/**
* sd_read_block_characteristics - Query block dev. characteristics
* @disk: disk to query
*/
@@ -1854,6 +1877,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
*/
if (sdkp->media_present) {
sd_read_capacity(sdkp, buffer);
+ sd_read_block_limits(sdkp);
sd_read_block_characteristics(sdkp);
sd_read_write_protect_flag(sdkp, buffer);
sd_read_cache_type(sdkp, buffer);
--
1.6.0.6
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