ide-cd: remove dead dsc_overlap setting

dsc_overlap setting is not useful anymore for ide-cd so remove
"dsc_overlap" /proc setting, disallow changing the setting through
HDIO_SET_NICE ioctl and cleanup ide_cd{rom_setup,_release}().

Cc: Borislav Petkov <petkovbb@googlemail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

drivers/ide/ide-cd.c

@@ -1831,21 +1831,14 @@ static ide_proc_entry_t idecd_proc[] = {
 	{ NULL, 0, NULL, NULL }
 };
 
-ide_devset_rw_flag(dsc_overlap, IDE_DFLAG_DSC_OVERLAP);
-
-static const struct ide_proc_devset idecd_settings[] = {
-	IDE_PROC_DEVSET(dsc_overlap, 0, 1),
-	{ 0 },
-};
-
 static ide_proc_entry_t *ide_cd_proc_entries(ide_drive_t *drive)
 {
 	return idecd_proc;
 }
 
 static const struct ide_proc_devset *ide_cd_proc_devsets(ide_drive_t *drive)
 {
-	return idecd_settings;
+	return NULL;
 }
 #endif
 
@@ -1945,11 +1938,6 @@ static int ide_cdrom_setup(ide_drive_t *drive)
 	/* set correct block size */
 	blk_queue_hardsect_size(drive->queue, CD_FRAMESIZE);
 
-	if (drive->next != drive)
-		drive->dev_flags |= IDE_DFLAG_DSC_OVERLAP;
-	else
-		drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
-
 	if (ide_cdrom_register(drive, nslots)) {
 		printk(KERN_ERR PFX "%s: %s failed to register device with the"
 				" cdrom driver.\n", drive->name, __func__);
@@ -1986,7 +1974,6 @@ static void ide_cd_release(struct kref *kref)
 	kfree(info->toc);
 	if (devinfo->handle == drive)
 		unregister_cdrom(devinfo);
-	drive->dev_flags &= ~IDE_DFLAG_DSC_OVERLAP;
 	drive->driver_data = NULL;
 	blk_queue_prep_rq(drive->queue, NULL);
 	g->private_data = NULL;

drivers/ide/ide-ioctls.c

@@ -95,7 +95,7 @@ static int ide_set_nice_ioctl(ide_drive_t *drive, unsigned long arg)
 		return -EPERM;
 
 	if (((arg >> IDE_NICE_DSC_OVERLAP) & 1) &&
-	    (drive->media == ide_disk || drive->media == ide_floppy ||
+	    (drive->media != ide_tape ||
 	     (drive->dev_flags & IDE_DFLAG_SCSI)))
 		return -EPERM;