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>

4 files changed, 12 insertions, 25 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
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index e053e00a7058..2711b5a6962d 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -221,7 +221,6 @@ static ide_startstop_t ide_start_power_step(ide_drive_t *drive, struct request *
                  */
                 if (drive->hwif->ide_dma_on == NULL)
                         break;
-                drive->hwif->dma_off_quietly(drive);
                 /*
                  * TODO: respect ->using_dma setting
                  */
diff --git a/drivers/ide/ide-probe.c b/drivers/ide/ide-probe.c
index 33e62d28465d..0379d1f697cf 100644
--- a/drivers/ide/ide-probe.c
+++ b/drivers/ide/ide-probe.c
@@ -833,16 +833,8 @@ static void probe_hwif(ide_hwif_t *hwif)
 
                         drive->nice1 = 1;
 
-                        if (hwif->ide_dma_on) {
-                                /*
-                                 * 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);
+                        if (hwif->ide_dma_on)
                                 ide_set_dma(drive);
-                        }
                 }
         }
 
diff --git a/drivers/ide/ide.c b/drivers/ide/ide.c
index 00ef6ec2c273..c6d4f630e18a 100644
--- a/drivers/ide/ide.c
+++ b/drivers/ide/ide.c
@@ -851,7 +851,6 @@ int set_using_dma(ide_drive_t *drive, int arg)
         err = 0;
 
         if (arg) {
-                hwif->dma_off_quietly(drive);
                 if (ide_set_dma(drive))
                         err = -EIO;
         } else