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, 1 insertions, 4 deletions

diff --git a/drivers/ide/pci/sc1200.c b/drivers/ide/pci/sc1200.c
index 8d762d323f8b..08e317f281e7 100644
--- a/drivers/ide/pci/sc1200.c
+++ b/drivers/ide/pci/sc1200.c
@@ -241,10 +241,7 @@ static int sc1200_config_dma2 (ide_drive_t *drive, int mode)
 
         outb(inb(hwif->dma_base+2)|(unit?0x40:0x20), hwif->dma_base+2); /* set DMA_capable bit */
 
-        /*
-         * Finally, turn DMA on in software, and exit.
-         */
-        return hwif->ide_dma_on(drive); /* success */
+        return 0;       /* success */
 }
 
 /*