[PATCH v5 15/27] ata: let compiler optimize out ata_eh_set_lpm() on non-SATA hosts

From: Bartlomiej Zolnierkiewicz
Date: Thu Mar 26 2020 - 11:59:56 EST


Add !IS_ENABLED(CONFIG_SATA_HOST) to ata_eh_set_lpm() to allow
compiler to optimize out the function for non-SATA configs (for
PATA hosts "ap && !ap->ops->set_lpm" condition is always true so
it's sufficient for the function to return zero).

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

text data bss dec hex filename
before:
17353 18 0 17371 43db drivers/ata/libata-eh.o
after:
16607 18 0 16625 40f1 drivers/ata/libata-eh.o

Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
---
drivers/ata/libata-eh.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 04275f4c8d36..8dc33b6832f0 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -3443,7 +3443,8 @@ static int ata_eh_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
int rc;

/* if the link or host doesn't do LPM, noop */
- if ((link->flags & ATA_LFLAG_NO_LPM) || (ap && !ap->ops->set_lpm))
+ if (!IS_ENABLED(CONFIG_SATA_HOST) ||
+ (link->flags & ATA_LFLAG_NO_LPM) || (ap && !ap->ops->set_lpm))
return 0;

/*
--
2.24.1