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, 12 insertions, 10 deletions

diff --git a/drivers/ata/sata_sis.c b/drivers/ata/sata_sis.c
index 33716b00c6b7..31a2f55aae66 100644
--- a/drivers/ata/sata_sis.c
+++ b/drivers/ata/sata_sis.c
@@ -64,8 +64,8 @@ enum {
 };
 
 static int sis_init_one (struct pci_dev *pdev, const struct pci_device_id *ent);
-static u32 sis_scr_read (struct ata_port *ap, unsigned int sc_reg);
-static void sis_scr_write (struct ata_port *ap, unsigned int sc_reg, u32 val);
+static int sis_scr_read (struct ata_port *ap, unsigned int sc_reg, u32 *val);
+static int sis_scr_write (struct ata_port *ap, unsigned int sc_reg, u32 val);
 
 static const struct pci_device_id sis_pci_tbl[] = {
         { PCI_VDEVICE(SI, 0x0180), sis_180 },           /* SiS 964/180 */
@@ -207,36 +207,37 @@ static void sis_scr_cfg_write (struct ata_port *ap, unsigned int sc_reg, u32 val
                 pci_write_config_dword(pdev, cfg_addr+0x10, val);
 }
 
-static u32 sis_scr_read (struct ata_port *ap, unsigned int sc_reg)
+static int sis_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val)
 {
         struct pci_dev *pdev = to_pci_dev(ap->host->dev);
-        u32 val, val2 = 0;
         u8 pmr;
 
         if (sc_reg > SCR_CONTROL)
-                return 0xffffffffU;
+                return -EINVAL;
 
         if (ap->flags & SIS_FLAG_CFGSCR)
                 return sis_scr_cfg_read(ap, sc_reg);
 
         pci_read_config_byte(pdev, SIS_PMR, &pmr);
 
-        val = ioread32(ap->ioaddr.scr_addr + (sc_reg * 4));
+        *val = ioread32(ap->ioaddr.scr_addr + (sc_reg * 4));
 
         if ((pdev->device == 0x0182) || (pdev->device == 0x0183) ||
             (pdev->device == 0x1182) || (pmr & SIS_PMR_COMBINED))
-                val2 = ioread32(ap->ioaddr.scr_addr + (sc_reg * 4) + 0x10);
+                *val |= ioread32(ap->ioaddr.scr_addr + (sc_reg * 4) + 0x10);
+
+        *val &= 0xfffffffb;
 
-        return (val | val2) &  0xfffffffb;
+        return 0;
 }
 
-static void sis_scr_write (struct ata_port *ap, unsigned int sc_reg, u32 val)
+static int sis_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val)
 {
         struct pci_dev *pdev = to_pci_dev(ap->host->dev);
         u8 pmr;
 
         if (sc_reg > SCR_CONTROL)
-                return;
+                return -EINVAL;
 
         pci_read_config_byte(pdev, SIS_PMR, &pmr);
 
@@ -248,6 +249,7 @@ static void sis_scr_write (struct ata_port *ap, unsigned int sc_reg, u32 val)
                     (pdev->device == 0x1182) || (pmr & SIS_PMR_COMBINED))
                         iowrite32(val, ap->ioaddr.scr_addr + (sc_reg * 4)+0x10);
         }
+        return 0;
 }
 
 static int sis_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)