On Wed, Dec 26, 2018 at 12:15:04PM +0800, Randall Huang wrote:
> In SPC-3, WRITE(10)/(16) support grouping function.
> Let's associate bio write hint with group number for
> enabling StreamID or Turbo Write feature.
>
> Signed-off-by: Randall Huang <huangrandall@xxxxxxxxxx>
> ---
> drivers/scsi/sd.c | 14 ++++++++++++--
> 1 file changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
> index 4b49cb67617e..28bfa9ed2b54 100644
> --- a/drivers/scsi/sd.c
> +++ b/drivers/scsi/sd.c
> @@ -1201,7 +1201,12 @@ static int sd_setup_read_write_cmnd(struct scsi_cmnd *SCpnt)
> SCpnt->cmnd[11] = (unsigned char) (this_count >> 16) & 0xff;
> SCpnt->cmnd[12] = (unsigned char) (this_count >> 8) & 0xff;
> SCpnt->cmnd[13] = (unsigned char) this_count & 0xff;
> - SCpnt->cmnd[14] = SCpnt->cmnd[15] = 0;
> + if (rq_data_dir(rq) == WRITE) {
> + SCpnt->cmnd[14] = rq->bio->bi_write_hint & 0x3f;
> + } else {
> + SCpnt->cmnd[14] = 0;
> + }
No need for braces here.
But what I'm more worried about is devices not recognizing the feature
throwing up on the field. Can you check what SBC version first
references these or come up with some other decently smart conditional?
Maybe Martin has a good idea, too.
