[PATCH] libata: update ata_do_simple_cmd()

* the function has always returned AC_ERR_* masks not -errno but its
  return type was int.  Make return type unsigned int.

* don't print error message automatically.  it's the caller's
  responsibility.

* add header comment

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

1 files changed, 43 insertions, 14 deletions

diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index bbd6665eb212..4a44e759e45a 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -1131,14 +1131,23 @@ unsigned ata_exec_internal(struct ata_device *dev,
         return err_mask;
 }
 
-/*
- * Execute a 'simple' command, that only consists of the opcode 'cmd' itself,
- * without filling any other registers
+/**
+ *      ata_do_simple_cmd - execute simple internal command
+ *      @dev: Device to which the command is sent
+ *      @cmd: Opcode to execute
+ *
+ *      Execute a 'simple' command, that only consists of the opcode
+ *      'cmd' itself, without filling any other registers
+ *
+ *      LOCKING:
+ *      Kernel thread context (may sleep).
+ *
+ *      RETURNS:
+ *      Zero on success, AC_ERR_* mask on failure
  */
-static int ata_do_simple_cmd(struct ata_device *dev, u8 cmd)
+static unsigned int ata_do_simple_cmd(struct ata_device *dev, u8 cmd)
 {
         struct ata_taskfile tf;
-        int err;
 
         ata_tf_init(dev, &tf);
 
@@ -1146,12 +1155,7 @@ static int ata_do_simple_cmd(struct ata_device *dev, u8 cmd)
         tf.flags |= ATA_TFLAG_DEVICE;
         tf.protocol = ATA_PROT_NODATA;
 
-        err = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0);
-        if (err)
-                ata_dev_printk(dev, KERN_ERR, "%s: ata command failed: %d\n",
-                               __FUNCTION__, err);
-
-        return err;
+        return ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0);
 }
 
 /**
@@ -4971,6 +4975,7 @@ int ata_port_offline(struct ata_port *ap)
 
 static int ata_flush_cache(struct ata_device *dev)
 {
+        unsigned int err_mask;
         u8 cmd;
 
         if (!ata_try_flush_cache(dev))
@@ -4981,17 +4986,41 @@ static int ata_flush_cache(struct ata_device *dev)
         else
                 cmd = ATA_CMD_FLUSH;
 
-        return ata_do_simple_cmd(dev, cmd);
+        err_mask = ata_do_simple_cmd(dev, cmd);
+        if (err_mask) {
+                ata_dev_printk(dev, KERN_ERR, "failed to flush cache\n");
+                return -EIO;
+        }
+
+        return 0;
 }
 
 static int ata_standby_drive(struct ata_device *dev)
 {
-        return ata_do_simple_cmd(dev, ATA_CMD_STANDBYNOW1);
+        unsigned int err_mask;
+
+        err_mask = ata_do_simple_cmd(dev, ATA_CMD_STANDBYNOW1);
+        if (err_mask) {
+                ata_dev_printk(dev, KERN_ERR, "failed to standby drive "
+                               "(err_mask=0x%x)\n", err_mask);
+                return -EIO;
+        }
+
+        return 0;
 }
 
 static int ata_start_drive(struct ata_device *dev)
 {
-        return ata_do_simple_cmd(dev, ATA_CMD_IDLEIMMEDIATE);
+        unsigned int err_mask;
+
+        err_mask = ata_do_simple_cmd(dev, ATA_CMD_IDLEIMMEDIATE);
+        if (err_mask) {
+                ata_dev_printk(dev, KERN_ERR, "failed to start drive "
+                               "(err_mask=0x%x)\n", err_mask);
+                return -EIO;
+        }
+
+        return 0;
 }
 
 /**