ide: add ide_tune_dma() helper

After reworking the code responsible for selecting the best DMA
transfer mode it is now possible to add generic ide_tune_dma() helper.

Convert some IDE PCI host drivers to use it (the ones left need more work).

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/drivers/ide/ide-dma.c b/drivers/ide/ide-dma.c
index f28fabb791fe..5fe85191d49c 100644
--- a/drivers/ide/ide-dma.c
+++ b/drivers/ide/ide-dma.c
@@ -779,6 +779,26 @@ u8 ide_max_dma_mode(ide_drive_t *drive)
 
 EXPORT_SYMBOL_GPL(ide_max_dma_mode);
 
+int ide_tune_dma(ide_drive_t *drive)
+{
+        u8 speed;
+
+        /* TODO: use only ide_max_dma_mode() */
+        if (!ide_use_dma(drive))
+                return 0;
+
+        speed = ide_max_dma_mode(drive);
+
+        if (!speed)
+                return 0;
+
+        drive->hwif->speedproc(drive, speed);
+
+        return ide_dma_enable(drive);
+}
+
+EXPORT_SYMBOL_GPL(ide_tune_dma);
+
 void ide_dma_verbose(ide_drive_t *drive)
 {
         struct hd_driveid *id   = drive->id;