[PATCH 5/6] libata: don't call ata_scsi_rbuf_fill for command without a response buffer

Christoph Hellwig
2017-01-10T08:42:10Z

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>
---
drivers/ata/libata-scsi.c | 22 +---------------------
1 file changed, 1 insertion(+), 21 deletions(-)

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 6078bc2..395c859 100644
--- 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;

--
2.1.4