ide: add ide_set_dma() helper (v2)

* add ide_set_dma() helper and make ide_hwif_t.ide_dma_check return
  -1 when DMA needs to be disabled (== need to call ->ide_dma_off_quietly)
   0 when DMA needs to be enabled  (== need to call ->ide_dma_on)
   1 when DMA setting shouldn't be changed
* fix IDE code to use ide_set_dma() instead if using ->ide_dma_check directly

v2:
* updated for scc_pata

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 2 insertions, 3 deletions

diff --git a/drivers/ide/pci/cs5535.c b/drivers/ide/pci/cs5535.c
index cd7c4190ad6e..45f43efbf92c 100644
--- a/drivers/ide/pci/cs5535.c
+++ b/drivers/ide/pci/cs5535.c
@@ -195,20 +195,19 @@ static int cs5535_config_drive_for_dma(ide_drive_t *drive)
 
 static int cs5535_dma_check(ide_drive_t *drive)
 {
-        ide_hwif_t *hwif        = drive->hwif;
         u8 speed;
 
         drive->init_speed = 0;
 
         if (ide_use_dma(drive) && cs5535_config_drive_for_dma(drive))
-                return hwif->ide_dma_on(drive);
+                return 0;
 
         if (ide_use_fast_pio(drive)) {
                 speed = ide_get_best_pio_mode(drive, 255, 4, NULL);
                 cs5535_set_drive(drive, speed);
         }
 
-        return hwif->ide_dma_off_quietly(drive);
+        return -1;
 }
 
 static u8 __devinit cs5535_cable_detect(struct pci_dev *dev)