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, 3 insertions, 3 deletions

diff --git a/drivers/ide/pci/sl82c105.c b/drivers/ide/pci/sl82c105.c
index c7025858f237..27b21e120260 100644
--- a/drivers/ide/pci/sl82c105.c
+++ b/drivers/ide/pci/sl82c105.c
@@ -161,14 +161,14 @@ static int sl82c105_check_drive (ide_drive_t *drive)
                 if (id->field_valid & 2) {
                         if ((id->dma_mword & hwif->mwdma_mask) ||
                             (id->dma_1word & hwif->swdma_mask))
-                                return hwif->ide_dma_on(drive);
+                                return 0;
                 }
 
                 if (__ide_dma_good_drive(drive) && id->eide_dma_time < 150)
-                        return hwif->ide_dma_on(drive);
+                        return 0;
         } while (0);
 
-        return hwif->ide_dma_off_quietly(drive);
+        return -1;
 }
 
 /*