ide: switch set_xfer_rate() to use REQ_TYPE_ATA_TASKFILE requests

Based on the earlier work by Tejun Heo.

Switch set_xfer_rate() to use REQ_TYPE_ATA_TASKFILE requests
and make ide_wait_cmd() static.

There should be no functionality changes caused by this patch.

Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

drivers/ide/ide-proc.c

@@ -346,14 +346,20 @@ static int ide_write_setting(ide_drive_t *drive, ide_settings_t *setting, int va
 
 static int set_xfer_rate (ide_drive_t *drive, int arg)
 {
+	ide_task_t task;
 	int err;
 
 	if (arg < 0 || arg > 70)
 		return -EINVAL;
 
-	err = ide_wait_cmd(drive,
-			WIN_SETFEATURES, (u8) arg,
-			SETFEATURES_XFER, 0, NULL);
+	memset(&task, 0, sizeof(task));
+	task.tf.command = WIN_SETFEATURES;
+	task.tf.feature = SETFEATURES_XFER;
+	task.tf.nsect   = (u8)arg;
+	task.tf_flags = IDE_TFLAG_OUT_FEATURE | IDE_TFLAG_OUT_NSECT |
+			IDE_TFLAG_IN_NSECT;
+
+	err = ide_no_data_taskfile(drive, &task);
 
 	if (!err && arg) {
 		ide_set_xfer_rate(drive, (u8) arg);

drivers/ide/ide-taskfile.c

@@ -750,7 +750,8 @@ abort:
 }
 #endif
 
-int ide_wait_cmd (ide_drive_t *drive, u8 cmd, u8 nsect, u8 feature, u8 sectors, u8 *buf)
+static int ide_wait_cmd(ide_drive_t *drive, u8 cmd, u8 nsect, u8 feature,
+			u8 sectors, u8 *buf)
 {
 	struct request rq;
 	u8 buffer[4];

include/linux/ide.h

@@ -870,14 +870,6 @@ extern int ide_do_drive_cmd(ide_drive_t *, struct request *, ide_action_t);
 
 extern void ide_end_drive_cmd(ide_drive_t *, u8, u8);
 
-/*
- * Issue ATA command and wait for completion.
- * Use for implementing commands in kernel
- *
- *  (ide_drive_t *drive, u8 cmd, u8 nsect, u8 feature, u8 sectors, u8 *buf)
- */
-extern int ide_wait_cmd(ide_drive_t *, u8, u8, u8, u8, u8 *);
-
 enum {
 	IDE_TFLAG_LBA48			= (1 << 0),
 	IDE_TFLAG_NO_SELECT_MASK	= (1 << 1),