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_qstor.c b/drivers/ata/sata_qstor.c
index 5aef4ac37012..c8f9242e7f44 100644
--- a/drivers/ata/sata_qstor.c
+++ b/drivers/ata/sata_qstor.c
@@ -111,8 +111,8 @@ struct qs_port_priv {
         qs_state_t              state;
 };
 
-static u32 qs_scr_read (struct ata_port *ap, unsigned int sc_reg);
-static void qs_scr_write (struct ata_port *ap, unsigned int sc_reg, u32 val);
+static int qs_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val);
+static int qs_scr_write(struct ata_port *ap, unsigned int sc_reg, u32 val);
 static int qs_ata_init_one (struct pci_dev *pdev, const struct pci_device_id *ent);
 static int qs_port_start(struct ata_port *ap);
 static void qs_host_stop(struct ata_host *host);
@@ -255,18 +255,20 @@ static void qs_eng_timeout(struct ata_port *ap)
         ata_eng_timeout(ap);
 }
 
-static u32 qs_scr_read (struct ata_port *ap, unsigned int sc_reg)
+static int qs_scr_read(struct ata_port *ap, unsigned int sc_reg, u32 *val)
 {
         if (sc_reg > SCR_CONTROL)
-                return ~0U;
-        return readl(ap->ioaddr.scr_addr + (sc_reg * 8));
+                return -EINVAL;
+        *val = readl(ap->ioaddr.scr_addr + (sc_reg * 8));
+        return 0;
 }
 
-static void qs_scr_write (struct ata_port *ap, unsigned int sc_reg, u32 val)
+static int qs_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 * 8));
+        return 0;
 }
 
 static unsigned int qs_fill_sg(struct ata_queued_cmd *qc)