ide: remove 'tf_in_flags' field from ide_task_t

* Add IDE_TFLAG_IN_DATA taskfile flag to indicate the need of reading
  IDE_DATA_REG in ide_end_drive_cmd().

  Set the new flag in ide_taskfile_ioctl() if ->in_flags.b.data is set.

* Add IDE_TFLAG_FLAGGED_SET_IN_FLAGS taskfile flag to indicate the
  need of modifying ->in_flags in ide_taskfile_ioctl().

  Set the new flag in flagged_taskfile() and move the code modifying
  ->tf_in_flags to ide_taskfile_ioctl().

  While at it remove the bogus comment: ->tf_in_flags (except .b.data)
  have no effect on selection of registers to read.

* Remove no longer needed 'tf_in_flags' field from ide_task_t.

As the result we finally have the internals of HDIO_DRIVE_TASKFILE ioctl
separated from the core IDE code.

There should be no functionality changes caused by this patch.

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c
index ff28449..03c4a0c 100644
--- a/drivers/ide/ide-taskfile.c
+++ b/drivers/ide/ide-taskfile.c
@@ -599,8 +599,8 @@
 
 	memcpy(&args.tf_array[0], req_task->hob_ports, HDIO_DRIVE_HOB_HDR_SIZE - 2);
 	memcpy(&args.tf_array[6], req_task->io_ports, HDIO_DRIVE_TASK_HDR_SIZE);
-	args.tf_in_flags  = req_task->in_flags;
-	args.data_phase   = req_task->data_phase;
+
+	args.data_phase = req_task->data_phase;
 
 	args.tf_flags = IDE_TFLAG_OUT_DEVICE;
 	if (drive->addressing == 1)
@@ -637,6 +637,9 @@
 			args.tf_flags |= IDE_TFLAG_OUT_HOB;
 	}
 
+	if (req_task->in_flags.b.data)
+		args.tf_flags |= IDE_TFLAG_IN_DATA;
+
 	drive->io_32bit = 0;
 	switch(req_task->data_phase) {
 		case TASKFILE_MULTI_OUT:
@@ -704,7 +707,13 @@
 
 	memcpy(req_task->hob_ports, &args.tf_array[0], HDIO_DRIVE_HOB_HDR_SIZE - 2);
 	memcpy(req_task->io_ports, &args.tf_array[6], HDIO_DRIVE_TASK_HDR_SIZE);
-	req_task->in_flags  = args.tf_in_flags;
+
+	if ((args.tf_flags & IDE_TFLAG_FLAGGED_SET_IN_FLAGS) &&
+	    req_task->in_flags.all == 0) {
+		req_task->in_flags.all = IDE_TASKFILE_STD_IN_FLAGS;
+		if (drive->addressing == 1)
+			req_task->in_flags.all |= (IDE_HOB_STD_IN_FLAGS << 8);
+	}
 
 	if (copy_to_user(buf, req_task, tasksize)) {
 		err = -EFAULT;
@@ -846,19 +855,7 @@
 		}
 	}
 
-	/*
-	 * (ks) Check taskfile in flags.
-	 * If set, then execute as it is defined.
-	 * If not set, then define default settings.
-	 * The default values are:
-	 *	read all taskfile registers (except data)
-	 *	read the hob registers (sector, nsector, lcyl, hcyl)
-	 */
-	if (task->tf_in_flags.all == 0) {
-		task->tf_in_flags.all = IDE_TASKFILE_STD_IN_FLAGS;
-		if (drive->addressing == 1)
-			task->tf_in_flags.all |= (IDE_HOB_STD_IN_FLAGS  << 8);
-        }
+	task->tf_flags |= IDE_TFLAG_FLAGGED_SET_IN_FLAGS;
 
 	return do_rw_taskfile(drive, task);
 }