icside: use ide_tune_dma()

* Add "good DMA drives" hack for icside to ide-dma.c::ide_find_dma_mode()
  (in the long-term it should be either removed or generalized for all hosts).

* Use ide_tune_dma() in icside.c::icside_dma_check().

  This results in the following changes in behavior:
  - pre-EIDE SWDMA modes are now also respected
  - drive->autodma is checked instead of hwif->autodma
    (doesn't really matter as icside sets both to "1")

* Make ide-dma.c::__ide_dma_good_drive() static and drop "__" prefix.

Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-dma.c b/drivers/ide/ide-dma.c
index 6000c08f..05781fa 100644
--- a/drivers/ide/ide-dma.c
+++ b/drivers/ide/ide-dma.c
@@ -169,6 +169,11 @@
 
 EXPORT_SYMBOL_GPL(ide_dma_intr);
 
+static int ide_dma_good_drive(ide_drive_t *drive)
+{
+	return ide_in_drive_list(drive->id, drive_whitelist);
+}
+
 #ifdef CONFIG_BLK_DEV_IDEDMA_PCI
 /**
  *	ide_build_sglist	-	map IDE scatter gather for DMA I/O
@@ -357,7 +362,7 @@
 				return 0;
 
 		/* Consult the list of known "good" drives */
-		if (__ide_dma_good_drive(drive))
+		if (ide_dma_good_drive(drive))
 			return 0;
 	}
 
@@ -639,14 +644,6 @@
 
 EXPORT_SYMBOL(__ide_dma_bad_drive);
 
-int __ide_dma_good_drive (ide_drive_t *drive)
-{
-	struct hd_driveid *id = drive->id;
-	return ide_in_drive_list(id, drive_whitelist);
-}
-
-EXPORT_SYMBOL(__ide_dma_good_drive);
-
 static const u8 xfer_mode_bases[] = {
 	XFER_UDMA_0,
 	XFER_MW_DMA_0,
@@ -746,6 +743,14 @@
 		}
 	}
 
+	if (hwif->chipset == ide_acorn && mode == 0) {
+		/*
+		 * is this correct?
+		 */
+		if (ide_dma_good_drive(drive) && drive->id->eide_dma_time < 150)
+			mode = XFER_MW_DMA_1;
+	}
+
 	printk(KERN_DEBUG "%s: selected mode 0x%x\n", drive->name, mode);
 
 	return min(mode, req_mode);