1 files changed, 50 insertions, 26 deletions

diff --git a/drivers/ide/ide-dma.c b/drivers/ide/ide-dma.c
index ff644a5e12c..b453211ee0f 100644
--- a/drivers/ide/ide-dma.c
+++ b/drivers/ide/ide-dma.c
@@ -169,6 +169,11 @@ ide_startstop_t ide_dma_intr (ide_drive_t *drive)
 
 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 @@ static int config_drive_for_dma (ide_drive_t *drive)
 				return 0;
 
 		/* Consult the list of known "good" drives */
-		if (__ide_dma_good_drive(drive))
+		if (ide_dma_good_drive(drive))
 			return 0;
 	}
 
@@ -639,21 +644,13 @@ int __ide_dma_bad_drive (ide_drive_t *drive)
 
 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,
 	XFER_SW_DMA_0,
 };
 
-static unsigned int ide_get_mode_mask(ide_drive_t *drive, u8 base)
+static unsigned int ide_get_mode_mask(ide_drive_t *drive, u8 base, u8 req_mode)
 {
 	struct hd_driveid *id = drive->id;
 	ide_hwif_t *hwif = drive->hwif;
@@ -664,17 +661,28 @@ static unsigned int ide_get_mode_mask(ide_drive_t *drive, u8 base)
 		if ((id->field_valid & 4) == 0)
 			break;
 
-		mask = id->dma_ultra & hwif->ultra_mask;
-
 		if (hwif->udma_filter)
-			mask &= hwif->udma_filter(drive);
+			mask = hwif->udma_filter(drive);
+		else
+			mask = hwif->ultra_mask;
+		mask &= id->dma_ultra;
 
-		if ((mask & 0x78) && (eighty_ninty_three(drive) == 0))
-			mask &= 0x07;
+		/*
+		 * avoid false cable warning from eighty_ninty_three()
+		 */
+		if (req_mode > XFER_UDMA_2) {
+			if ((mask & 0x78) && (eighty_ninty_three(drive) == 0))
+				mask &= 0x07;
+		}
 		break;
 	case XFER_MW_DMA_0:
-		if (id->field_valid & 2)
-			mask = id->dma_mword & hwif->mwdma_mask;
+		if ((id->field_valid & 2) == 0)
+			break;
+		if (hwif->mdma_filter)
+			mask = hwif->mdma_filter(drive);
+		else
+			mask = hwif->mwdma_mask;
+		mask &= id->dma_mword;
 		break;
 	case XFER_SW_DMA_0:
 		if (id->field_valid & 2) {
@@ -703,15 +711,18 @@ static unsigned int ide_get_mode_mask(ide_drive_t *drive, u8 base)
 }
 
 /**
- *	ide_max_dma_mode	-	compute DMA speed
+ *	ide_find_dma_mode	-	compute DMA speed
  *	@drive: IDE device
+ *	@req_mode: requested mode
  *
- *	Checks the drive capabilities and returns the speed to use
- *	for the DMA transfer.  Returns 0 if the drive is incapable
- *	of DMA transfers.
+ *	Checks the drive/host capabilities and finds the speed to use for
+ *	the DMA transfer.  The speed is then limited by the requested mode.
+ *
+ *	Returns 0 if the drive/host combination is incapable of DMA transfers
+ *	or if the requested mode is not a DMA mode.
  */
 
-u8 ide_max_dma_mode(ide_drive_t *drive)
+u8 ide_find_dma_mode(ide_drive_t *drive, u8 req_mode)
 {
 	ide_hwif_t *hwif = drive->hwif;
 	unsigned int mask;
@@ -722,7 +733,9 @@ u8 ide_max_dma_mode(ide_drive_t *drive)
 		return 0;
 
 	for (i = 0; i < ARRAY_SIZE(xfer_mode_bases); i++) {
-		mask = ide_get_mode_mask(drive, xfer_mode_bases[i]);
+		if (req_mode < xfer_mode_bases[i])
+			continue;
+		mask = ide_get_mode_mask(drive, xfer_mode_bases[i], req_mode);
 		x = fls(mask) - 1;
 		if (x >= 0) {
 			mode = xfer_mode_bases[i] + x;
@@ -730,12 +743,20 @@ u8 ide_max_dma_mode(ide_drive_t *drive)
 		}
 	}
 
+	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 mode;
+	return min(mode, req_mode);
 }
 
-EXPORT_SYMBOL_GPL(ide_max_dma_mode);
+EXPORT_SYMBOL_GPL(ide_find_dma_mode);
 
 int ide_tune_dma(ide_drive_t *drive)
 {
@@ -753,7 +774,10 @@ int ide_tune_dma(ide_drive_t *drive)
 	if (!speed)
 		return 0;
 
-	if (drive->hwif->speedproc(drive, speed))
+	if (drive->hwif->host_flags & IDE_HFLAG_NO_SET_MODE)
+		return 0;
+
+	if (ide_set_dma_mode(drive, speed))
 		return 0;
 
 	return 1;