libata: make ->scr_read/write callbacks return error code

Convert ->scr_read/write callbacks to return error code to better
indicate failure.  This will help handling of SCR_NOTIFICATION.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 7 insertions, 6 deletions

diff --git a/drivers/ata/sata_svw.c b/drivers/ata/sata_svw.c
index 63fe99afd59f..92e877075037 100644
--- a/drivers/ata/sata_svw.c
+++ b/drivers/ata/sata_svw.c
@@ -103,20 +103,21 @@ static int k2_sata_check_atapi_dma(struct ata_queued_cmd *qc)
         return 0;
 }
 
-static u32 k2_sata_scr_read (struct ata_port *ap, unsigned int sc_reg)
+static int k2_sata_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val)
 {
         if (sc_reg > SCR_CONTROL)
-                return 0xffffffffU;
-        return readl(ap->ioaddr.scr_addr + (sc_reg * 4));
+                return -EINVAL;
+        *val = readl(ap->ioaddr.scr_addr + (sc_reg * 4));
+        return 0;
 }
 
 
-static void k2_sata_scr_write (struct ata_port *ap, unsigned int sc_reg,
-                               u32 val)
+static int k2_sata_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val)
 {
         if (sc_reg > SCR_CONTROL)
-                return;
+                return -EINVAL;
         writel(val, ap->ioaddr.scr_addr + (sc_reg * 4));
+        return 0;
 }