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/arm/icside.c b/drivers/ide/arm/icside.c
index 61ce40d52f5f..aeed0205ce64 100644
--- a/drivers/ide/arm/icside.c
+++ b/drivers/ide/arm/icside.c
@@ -365,10 +365,7 @@ static int icside_dma_check(ide_drive_t *drive)
 out:
         on = icside_set_speed(drive, xfer_mode);
 
-        if (on)
-                return icside_dma_on(drive);
-        else
-                return icside_dma_off_quietly(drive);
+        return on ? 0 : -1;
 }
 
 static int icside_dma_end(ide_drive_t *drive)