libata: don't call ata_scsi_rbuf_fill for command without a response buffer

No need to copy a zeroed buffer to the caller if the command is defined
to not have a response in the SCSI spec.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 6078bc2..395c859 100644 (file)
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -2453,23 +2453,6 @@ static unsigned int ata_scsiop_inq_b6(struct ata_scsi_args *args, u8 *rbuf)
 }
 
 /**
- *     ata_scsiop_noop - Command handler that simply returns success.
- *     @args: device IDENTIFY data / SCSI command of interest.
- *     @rbuf: Response buffer, to which simulated SCSI cmd output is sent.
- *
- *     No operation.  Simply returns success to caller, to indicate
- *     that the caller should successfully complete this SCSI command.
- *
- *     LOCKING:
- *     spin_lock_irqsave(host lock)
- */
-static unsigned int ata_scsiop_noop(struct ata_scsi_args *args, u8 *rbuf)
-{
-       VPRINTK("ENTER\n");
-       return 0;
-}
-
-/**
  *     modecpy - Prepare response for MODE SENSE
  *     @dest: output buffer
  *     @src: data being copied
@@ -4425,14 +4408,11 @@ void ata_scsi_simulate(struct ata_device *dev, struct scsi_cmnd *cmd)
        case SEEK_6:
        case SEEK_10:
        case TEST_UNIT_READY:
-               ata_scsi_rbuf_fill(&args, ata_scsiop_noop);
                break;
 
        case SEND_DIAGNOSTIC:
                tmp8 = scsicmd[1] & ~(1 << 3);
-               if ((tmp8 == 0x4) && (!scsicmd[3]) && (!scsicmd[4]))
-                       ata_scsi_rbuf_fill(&args, ata_scsiop_noop);
-               else
+               if (tmp8 != 0x4 || scsicmd[3] || scsicmd[4])
                        ata_scsi_set_invalid_field(dev, cmd, 1, 0xff);
                break;