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, 9 insertions, 7 deletions

diff --git a/drivers/ata/sata_uli.c b/drivers/ata/sata_uli.c
index b52f83ab056a..78c28512f01c 100644
--- a/drivers/ata/sata_uli.c
+++ b/drivers/ata/sata_uli.c
@@ -57,8 +57,8 @@ struct uli_priv {
 };
 
 static int uli_init_one (struct pci_dev *pdev, const struct pci_device_id *ent);
-static u32 uli_scr_read (struct ata_port *ap, unsigned int sc_reg);
-static void uli_scr_write (struct ata_port *ap, unsigned int sc_reg, u32 val);
+static int uli_scr_read (struct ata_port *ap, unsigned int sc_reg, u32 *val);
+static int uli_scr_write (struct ata_port *ap, unsigned int sc_reg, u32 val);
 
 static const struct pci_device_id uli_pci_tbl[] = {
         { PCI_VDEVICE(AL, 0x5289), uli_5289 },
@@ -164,20 +164,22 @@ static void uli_scr_cfg_write (struct ata_port *ap, unsigned int scr, u32 val)
         pci_write_config_dword(pdev, cfg_addr, val);
 }
 
-static u32 uli_scr_read (struct ata_port *ap, unsigned int sc_reg)
+static int uli_scr_read (struct ata_port *ap, unsigned int sc_reg, u32 *val)
 {
         if (sc_reg > SCR_CONTROL)
-                return 0xffffffffU;
+                return -EINVAL;
 
-        return uli_scr_cfg_read(ap, sc_reg);
+        *val = uli_scr_cfg_read(ap, sc_reg);
+        return 0;
 }
 
-static void uli_scr_write (struct ata_port *ap, unsigned int sc_reg, u32 val)
+static int uli_scr_write (struct ata_port *ap, unsigned int sc_reg, u32 val)
 {
         if (sc_reg > SCR_CONTROL)       //SCR_CONTROL=2, SCR_ERROR=1, SCR_STATUS=0
-                return;
+                return -EINVAL;
 
         uli_scr_cfg_write(ap, sc_reg, val);
+        return 0;
 }
 
 static int uli_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)