From d11b6916961d6ec7d7215332cbbe9feec086721d Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Sat, 23 May 2009 11:43:39 -0400 Subject: [PATCH] sd: Block limits VPD support Query the block limits VPD page and adjust queue minimum and optimal I/O sizes. Signed-off-by: Martin K. Petersen Signed-off-by: James Bottomley --- drivers/scsi/sd.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 2148d659c281..e4ef11af18a2 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -1794,6 +1794,29 @@ void sd_read_app_tag_own(struct scsi_disk *sdkp, unsigned char *buffer) return; } +/** + * 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); -- 2.20.1