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, 4 insertions, 6 deletions

diff --git a/drivers/ide/pci/piix.c b/drivers/ide/pci/piix.c
index caf606a1ee86..569822f4cf55 100644
--- a/drivers/ide/pci/piix.c
+++ b/drivers/ide/pci/piix.c
@@ -386,19 +386,17 @@ static int piix_config_drive_for_dma (ide_drive_t *drive)
  
 static int piix_config_drive_xfer_rate (ide_drive_t *drive)
 {
-        ide_hwif_t *hwif        = HWIF(drive);
-
         drive->init_speed = 0;
 
         if (ide_use_dma(drive) && piix_config_drive_for_dma(drive))
-                return hwif->ide_dma_on(drive);
+                return 0;
 
         if (ide_use_fast_pio(drive))
                 /* Find best PIO mode. */
-                (void) hwif->speedproc(drive, XFER_PIO_0 +
-                                       ide_get_best_pio_mode(drive, 255, 4, NULL));
+                piix_tune_chipset(drive, XFER_PIO_0 +
+                                  ide_get_best_pio_mode(drive, 255, 4, NULL));
 
-        return hwif->ide_dma_off_quietly(drive);
+        return -1;
 }
 
 /**