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, 11 insertions, 6 deletions

diff --git a/drivers/ata/sata_sil24.c b/drivers/ata/sata_sil24.c
index e201f1cab66d..46fbbe7f121c 100644
--- a/drivers/ata/sata_sil24.c
+++ b/drivers/ata/sata_sil24.c
@@ -326,8 +326,8 @@ struct sil24_port_priv {
 
 static void sil24_dev_config(struct ata_device *dev);
 static u8 sil24_check_status(struct ata_port *ap);
-static u32 sil24_scr_read(struct ata_port *ap, unsigned sc_reg);
-static void sil24_scr_write(struct ata_port *ap, unsigned sc_reg, u32 val);
+static int sil24_scr_read(struct ata_port *ap, unsigned sc_reg, u32 *val);
+static int sil24_scr_write(struct ata_port *ap, unsigned sc_reg, u32 val);
 static void sil24_tf_read(struct ata_port *ap, struct ata_taskfile *tf);
 static void sil24_qc_prep(struct ata_queued_cmd *qc);
 static unsigned int sil24_qc_issue(struct ata_queued_cmd *qc);
@@ -488,25 +488,30 @@ static int sil24_scr_map[] = {
         [SCR_ACTIVE]    = 3,
 };
 
-static u32 sil24_scr_read(struct ata_port *ap, unsigned sc_reg)
+static int sil24_scr_read(struct ata_port *ap, unsigned sc_reg, u32 *val)
 {
         void __iomem *scr_addr = ap->ioaddr.scr_addr;
+
         if (sc_reg < ARRAY_SIZE(sil24_scr_map)) {
                 void __iomem *addr;
                 addr = scr_addr + sil24_scr_map[sc_reg] * 4;
-                return readl(scr_addr + sil24_scr_map[sc_reg] * 4);
+                *val = readl(scr_addr + sil24_scr_map[sc_reg] * 4);
+                return 0;
         }
-        return 0xffffffffU;
+        return -EINVAL;
 }
 
-static void sil24_scr_write(struct ata_port *ap, unsigned sc_reg, u32 val)
+static int sil24_scr_write(struct ata_port *ap, unsigned sc_reg, u32 val)
 {
         void __iomem *scr_addr = ap->ioaddr.scr_addr;
+
         if (sc_reg < ARRAY_SIZE(sil24_scr_map)) {
                 void __iomem *addr;
                 addr = scr_addr + sil24_scr_map[sc_reg] * 4;
                 writel(val, scr_addr + sil24_scr_map[sc_reg] * 4);
+                return 0;
         }
+        return -EINVAL;
 }
 
 static void sil24_tf_read(struct ata_port *ap, struct ata_taskfile *tf)