ide: cleanup ide_set_dma()

* ->dma_off_quietly is always called before ide_set_dma()
  so the call can be moved inside ide_set_dma().

* ide_dma_check() doesn't touch hardware so ->dma_off_quietly
  call for 'rc == -1' case is redundant, remove it.

* '0' and '-1' are the only values returned by ide_dma_check()
  so remove dead code for other cases.

There should be no functionality changes caused by this patch.

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 11 insertions, 14 deletions

diff --git a/drivers/ide/ide-dma.c b/drivers/ide/ide-dma.c
index 7568c3e81f2f..01036305d6fc 100644
--- a/drivers/ide/ide-dma.c
+++ b/drivers/ide/ide-dma.c
@@ -827,22 +827,19 @@ int ide_set_dma(ide_drive_t *drive)
         ide_hwif_t *hwif = drive->hwif;
         int rc;
 
-        rc = ide_dma_check(drive);
+        /*
+         * Force DMAing for the beginning of the check.
+         * Some chipsets appear to do interesting
+         * things, if not checked and cleared.
+         *   PARANOIA!!!
+         */
+        hwif->dma_off_quietly(drive);
 
-        switch(rc) {
-        case -1: /* DMA needs to be disabled */
-                hwif->dma_off_quietly(drive);
-                return -1;
-        case  0: /* DMA needs to be enabled */
-                return hwif->ide_dma_on(drive);
-        case  1: /* DMA setting cannot be changed */
-                break;
-        default:
-                BUG();
-                break;
-        }
+        rc = ide_dma_check(drive);
+        if (rc)
+                return rc;
 
-        return rc;
+        return hwif->ide_dma_on(drive);
 }
 
 #ifdef CONFIG_BLK_DEV_IDEDMA_PCI