libata: make SFF support optional
Now that SFF support is completely separated out from the core layer,
it can be made optional. Add CONFIG_ATA_SFF and let SFF drivers
depend on it. If CONFIG_ATA_SFF isn't set, all codes in libata-sff.c
and data structures for SFF support are disabled. This saves good
number of bytes for small systems.
Signed-off-by: Tejun Heo <htejun@gmail.com>
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index f8be928..a70881c 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -2393,7 +2393,9 @@
/* FIXME: is this needed? */
memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE);
+#ifdef CONFIG_ATA_SFF
ap->ops->sff_tf_read(ap, &qc->tf);
+#endif
/* fill these in, for the case where they are -not- overwritten */
cmd->sense_buffer[0] = 0x70;