Subject: [PATCH v5 13/27] ata: add CONFIG_SATA_HOST=n version of ata_ncq_enabled()

When CONFIG_SATA_HOST=n there are no NCQ capable host drivers
built so it is safe to hardwire ata_ncq_enabled() to always
return zero.

Code size savings on m68k arch using (modified) atari_defconfig:

text data bss dec hex filename
before:
37820 572 40 38432 9620 drivers/ata/libata-core.o
21040 105 576 21721 54d9 drivers/ata/libata-scsi.o
17405 18 0 17423 440f drivers/ata/libata-eh.o
after:
37582 572 40 38194 9532 drivers/ata/libata-core.o
20702 105 576 21383 5387 drivers/ata/libata-scsi.o
17353 18 0 17371 43db drivers/ata/libata-eh.o

Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Bartlomiej Zolnierkiewicz <[email protected]>
---
include/linux/libata.h | 2 ++
1 file changed, 2 insertions(+)

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 500b709ed3de..661d76038684 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -1633,6 +1633,8 @@ extern struct ata_device *ata_dev_next(struct ata_device *dev,
*/
static inline int ata_ncq_enabled(struct ata_device *dev)
{
+ if (!IS_ENABLED(CONFIG_SATA_HOST))
+ return 0;
return (dev->flags & (ATA_DFLAG_PIO | ATA_DFLAG_NCQ_OFF |
ATA_DFLAG_NCQ)) == ATA_DFLAG_NCQ;
}
--
2.24.1