From 7569e8dc2213ecc47024ea5edbadc8736487d926 Mon Sep 17 00:00:00 2001
From: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Date: Sat, 17 Feb 2007 02:40:25 +0100
Subject: [PATCH] ide: add ide_use_fast_pio() helper (v3)

* add ide_use_fast_pio() helper for use by host drivers

* add DMA capability and hwif->autodma checks to ide_use_dma()

  - au1xxx-ide/it8213/it821x drivers didn't check for (id->capability & 1)

    [ for the IT8211/2 in SMART mode this check shouldn't be made but since
      in it821x_fixups() we set DMA bit explicitly:

               if(strstr(id->model, "Integrated Technology Express")) {
                       /* In raid mode the ident block is slightly buggy
                          We need to set the bits so that the IDE layer knows
                          LBA28. LBA48 and DMA ar valid */
                       id->capability |= 3;            /* LBA28, DMA */

       we are better off using generic helper if we can ]

  - ide-cris driver didn't set ->autodma

    [ before the patch hwif->autodma was only checked in the chipset specific
      hwif->ide_dma_check implementations, for ide-cris it is cris_dma_check()
      function so there no behavior change here ]

v2:
* updated patch description (thanks to Alan Cox for the feedback)

v3:
* updated for scc_pata driver

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
---
 drivers/ide/cris/ide-cris.c    | 12 +++++-------
 drivers/ide/ide-dma.c          |  3 +++
 drivers/ide/ide-lib.c          | 15 +++++++++++++++
 drivers/ide/pci/aec62xx.c      | 14 +++-----------
 drivers/ide/pci/atiixp.c       | 14 +++-----------
 drivers/ide/pci/cmd64x.c       | 14 +++-----------
 drivers/ide/pci/cs5535.c       | 13 +++----------
 drivers/ide/pci/hpt34x.c       | 16 ++++------------
 drivers/ide/pci/hpt366.c       | 11 +++--------
 drivers/ide/pci/pdc202xx_new.c | 12 +++---------
 drivers/ide/pci/pdc202xx_old.c | 14 +++-----------
 drivers/ide/pci/piix.c         | 12 +++---------
 drivers/ide/pci/serverworks.c  | 14 +++-----------
 drivers/ide/pci/siimage.c      | 14 +++-----------
 drivers/ide/pci/sis5513.c      | 14 +++-----------
 drivers/ide/pci/slc90e66.c     | 12 +++---------
 drivers/ide/pci/tc86c001.c     | 12 +++---------
 drivers/ide/pci/triflex.c      |  9 ++-------
 drivers/ide/ppc/scc_pata.c     | 13 ++++---------
 include/linux/ide.h            |  1 +
 20 files changed, 73 insertions(+), 166 deletions(-)

diff --git a/drivers/ide/cris/ide-cris.c b/drivers/ide/cris/ide-cris.c
index 5797e0b5a132..7afb715b86e5 100644
--- a/drivers/ide/cris/ide-cris.c
+++ b/drivers/ide/cris/ide-cris.c
@@ -821,6 +821,9 @@ init_e100_ide (void)
 		hwif->ultra_mask = cris_ultra_mask;
 		hwif->mwdma_mask = 0x07; /* Multiword DMA 0-2 */
 		hwif->swdma_mask = 0x07; /* Singleword DMA 0-2 */
+		hwif->autodma = 1;
+		hwif->drives[0].autodma = 1;
+		hwif->drives[1].autodma = 1;
 	}
 
 	/* Reset pulse */
@@ -1046,14 +1049,9 @@ static ide_startstop_t cris_dma_intr (ide_drive_t *drive)
 static int cris_dma_check(ide_drive_t *drive)
 {
 	ide_hwif_t *hwif = drive->hwif;
-	struct hd_driveid* id = drive->id;
 
-	if (id && (id->capability & 1)) {
-		if (ide_use_dma(drive)) {
-			if (cris_config_drive_for_dma(drive))
-				return hwif->ide_dma_on(drive);
-		}
-	}
+	if (ide_use_dma(drive) && cris_config_drive_for_dma(drive))
+		return hwif->ide_dma_on(drive);
 
 	return hwif->ide_dma_off_quietly(drive);
 }
diff --git a/drivers/ide/ide-dma.c b/drivers/ide/ide-dma.c
index 56efed6742d4..941846c21624 100644
--- a/drivers/ide/ide-dma.c
+++ b/drivers/ide/ide-dma.c
@@ -680,6 +680,9 @@ int ide_use_dma(ide_drive_t *drive)
 	struct hd_driveid *id = drive->id;
 	ide_hwif_t *hwif = drive->hwif;
 
+	if ((id->capability & 1) == 0 || drive->autodma == 0)
+		return 0;
+
 	/* consult the list of known "bad" drives */
 	if (__ide_dma_bad_drive(drive))
 		return 0;
diff --git a/drivers/ide/ide-lib.c b/drivers/ide/ide-lib.c
index bea5e13ee361..8afce4ceea31 100644
--- a/drivers/ide/ide-lib.c
+++ b/drivers/ide/ide-lib.c
@@ -205,6 +205,21 @@ int ide_dma_enable (ide_drive_t *drive)
 
 EXPORT_SYMBOL(ide_dma_enable);
 
+int ide_use_fast_pio(ide_drive_t *drive)
+{
+	struct hd_driveid *id = drive->id;
+
+	if ((id->capability & 1) && drive->autodma)
+		return 1;
+
+	if ((id->capability & 8) || (id->field_valid & 2))
+		return 1;
+
+	return 0;
+}
+
+EXPORT_SYMBOL_GPL(ide_use_fast_pio);
+
 /*
  * Standard (generic) timings for PIO modes, from ATA2 specification.
  * These timings are for access to the IDE data port register *only*.
diff --git a/drivers/ide/pci/aec62xx.c b/drivers/ide/pci/aec62xx.c
index cac12c38b940..199507391ae8 100644
--- a/drivers/ide/pci/aec62xx.c
+++ b/drivers/ide/pci/aec62xx.c
@@ -210,19 +210,11 @@ static void aec62xx_tune_drive (ide_drive_t *drive, u8 pio)
 static int aec62xx_config_drive_xfer_rate (ide_drive_t *drive)
 {
 	ide_hwif_t *hwif	= HWIF(drive);
-	struct hd_driveid *id	= drive->id;
 
-	if ((id->capability & 1) && drive->autodma) {
+	if (ide_use_dma(drive) && config_chipset_for_dma(drive))
+		return hwif->ide_dma_on(drive);
 
-		if (ide_use_dma(drive)) {
-			if (config_chipset_for_dma(drive))
-				return hwif->ide_dma_on(drive);
-		}
-
-		goto fast_ata_pio;
-
-	} else if ((id->capability & 8) || (id->field_valid & 2)) {
-fast_ata_pio:
+	if (ide_use_fast_pio(drive)) {
 		aec62xx_tune_drive(drive, 5);
 		return hwif->ide_dma_off_quietly(drive);
 	}
diff --git a/drivers/ide/pci/atiixp.c b/drivers/ide/pci/atiixp.c
index 922b315da4a0..dfc738c42228 100644
--- a/drivers/ide/pci/atiixp.c
+++ b/drivers/ide/pci/atiixp.c
@@ -253,22 +253,14 @@ static int atiixp_config_drive_for_dma(ide_drive_t *drive)
 static int atiixp_dma_check(ide_drive_t *drive)
 {
 	ide_hwif_t *hwif	= HWIF(drive);
-	struct hd_driveid *id	= drive->id;
 	u8 tspeed, speed;
 
 	drive->init_speed = 0;
 
-	if ((id->capability & 1) && drive->autodma) {
+	if (ide_use_dma(drive) && atiixp_config_drive_for_dma(drive))
+		return hwif->ide_dma_on(drive);
 
-		if (ide_use_dma(drive)) {
-			if (atiixp_config_drive_for_dma(drive))
-				return hwif->ide_dma_on(drive);
-		}
-
-		goto fast_ata_pio;
-
-	} else if ((id->capability & 8) || (id->field_valid & 2)) {
-fast_ata_pio:
+	if (ide_use_fast_pio(drive)) {
 		tspeed = ide_get_best_pio_mode(drive, 255, 5, NULL);
 		speed = atiixp_dma_2_pio(XFER_PIO_0 + tspeed) + XFER_PIO_0;
 		hwif->speedproc(drive, speed);
diff --git a/drivers/ide/pci/cmd64x.c b/drivers/ide/pci/cmd64x.c
index 009fc9168443..b1f9f5f3615e 100644
--- a/drivers/ide/pci/cmd64x.c
+++ b/drivers/ide/pci/cmd64x.c
@@ -475,19 +475,11 @@ static int config_chipset_for_dma (ide_drive_t *drive)
 static int cmd64x_config_drive_for_dma (ide_drive_t *drive)
 {
 	ide_hwif_t *hwif	= HWIF(drive);
-	struct hd_driveid *id	= drive->id;
 
-	if ((id != NULL) && ((id->capability & 1) != 0) && drive->autodma) {
+	if (ide_use_dma(drive) && config_chipset_for_dma(drive))
+		return hwif->ide_dma_on(drive);
 
-		if (ide_use_dma(drive)) {
-			if (config_chipset_for_dma(drive))
-				return hwif->ide_dma_on(drive);
-		}
-
-		goto fast_ata_pio;
-
-	} else if ((id->capability & 8) || (id->field_valid & 2)) {
-fast_ata_pio:
+	if (ide_use_fast_pio(drive)) {
 		config_chipset_for_pio(drive, 1);
 		return hwif->ide_dma_off_quietly(drive);
 	}
diff --git a/drivers/ide/pci/cs5535.c b/drivers/ide/pci/cs5535.c
index 5c5aec28e671..e47653f4d1dd 100644
--- a/drivers/ide/pci/cs5535.c
+++ b/drivers/ide/pci/cs5535.c
@@ -196,21 +196,14 @@ static int cs5535_config_drive_for_dma(ide_drive_t *drive)
 static int cs5535_dma_check(ide_drive_t *drive)
 {
 	ide_hwif_t *hwif	= drive->hwif;
-	struct hd_driveid *id	= drive->id;
 	u8 speed;
 
 	drive->init_speed = 0;
 
-	if ((id->capability & 1) && drive->autodma) {
-		if (ide_use_dma(drive)) {
-			if (cs5535_config_drive_for_dma(drive))
-				return hwif->ide_dma_on(drive);
-		}
+	if (ide_use_dma(drive) && cs5535_config_drive_for_dma(drive))
+		return hwif->ide_dma_on(drive);
 
-		goto fast_ata_pio;
-
-	} else if ((id->capability & 8) || (id->field_valid & 2)) {
-fast_ata_pio:
+	if (ide_use_fast_pio(drive)) {
 		speed = ide_get_best_pio_mode(drive, 255, 4, NULL);
 		cs5535_set_drive(drive, speed);
 		return hwif->ide_dma_off_quietly(drive);
diff --git a/drivers/ide/pci/hpt34x.c b/drivers/ide/pci/hpt34x.c
index 0de3b61cabe3..0830089c77fd 100644
--- a/drivers/ide/pci/hpt34x.c
+++ b/drivers/ide/pci/hpt34x.c
@@ -110,25 +110,17 @@ static int config_chipset_for_dma (ide_drive_t *drive)
 static int hpt34x_config_drive_xfer_rate (ide_drive_t *drive)
 {
 	ide_hwif_t *hwif	= HWIF(drive);
-	struct hd_driveid *id	= drive->id;
 
 	drive->init_speed = 0;
 
-	if (id && (id->capability & 1) && drive->autodma) {
-
-		if (ide_use_dma(drive)) {
-			if (config_chipset_for_dma(drive))
+	if (ide_use_dma(drive) && config_chipset_for_dma(drive))
 #ifndef CONFIG_HPT34X_AUTODMA
-				return hwif->ide_dma_off_quietly(drive);
+		return hwif->ide_dma_off_quietly(drive);
 #else
-				return hwif->ide_dma_on(drive);
+		return hwif->ide_dma_on(drive);
 #endif
-		}
 
-		goto fast_ata_pio;
-
-	} else if ((id->capability & 8) || (id->field_valid & 2)) {
-fast_ata_pio:
+	if (ide_use_fast_pio(drive)) {
 		hpt34x_tune_drive(drive, 255);
 		return hwif->ide_dma_off_quietly(drive);
 	}
diff --git a/drivers/ide/pci/hpt366.c b/drivers/ide/pci/hpt366.c
index 06dce0999105..d3f6f9da96b2 100644
--- a/drivers/ide/pci/hpt366.c
+++ b/drivers/ide/pci/hpt366.c
@@ -737,18 +737,13 @@ static void hpt3xx_maskproc(ide_drive_t *drive, int mask)
 static int hpt366_config_drive_xfer_rate(ide_drive_t *drive)
 {
 	ide_hwif_t *hwif	= HWIF(drive);
-	struct hd_driveid *id	= drive->id;
 
 	drive->init_speed = 0;
 
-	if ((id->capability & 1) && drive->autodma) {
-		if (ide_use_dma(drive) && config_chipset_for_dma(drive))
-			return hwif->ide_dma_on(drive);
+	if (ide_use_dma(drive) && config_chipset_for_dma(drive))
+		return hwif->ide_dma_on(drive);
 
-		goto fast_ata_pio;
-
-	} else if ((id->capability & 8) || (id->field_valid & 2)) {
-fast_ata_pio:
+	if (ide_use_fast_pio(drive)) {
 		hpt3xx_tune_drive(drive, 255);
 		return hwif->ide_dma_off_quietly(drive);
 	}
diff --git a/drivers/ide/pci/pdc202xx_new.c b/drivers/ide/pci/pdc202xx_new.c
index 236a03144a27..b13a06c5cb2d 100644
--- a/drivers/ide/pci/pdc202xx_new.c
+++ b/drivers/ide/pci/pdc202xx_new.c
@@ -282,19 +282,13 @@ static int config_chipset_for_dma(ide_drive_t *drive)
 static int pdcnew_config_drive_xfer_rate(ide_drive_t *drive)
 {
 	ide_hwif_t *hwif	= HWIF(drive);
-	struct hd_driveid *id	= drive->id;
 
 	drive->init_speed = 0;
 
-	if ((id->capability & 1) && drive->autodma) {
+	if (ide_use_dma(drive) && config_chipset_for_dma(drive))
+		return hwif->ide_dma_on(drive);
 
-		if (ide_use_dma(drive) && config_chipset_for_dma(drive))
-			return hwif->ide_dma_on(drive);
-
-		goto fast_ata_pio;
-
-	} else if ((id->capability & 8) || (id->field_valid & 2)) {
-fast_ata_pio:
+	if (ide_use_fast_pio(drive)) {
 		hwif->tuneproc(drive, 255);
 		return hwif->ide_dma_off_quietly(drive);
 	}
diff --git a/drivers/ide/pci/pdc202xx_old.c b/drivers/ide/pci/pdc202xx_old.c
index 80eb6d271330..a2be3d2fd3f6 100644
--- a/drivers/ide/pci/pdc202xx_old.c
+++ b/drivers/ide/pci/pdc202xx_old.c
@@ -323,21 +323,13 @@ static int config_chipset_for_dma (ide_drive_t *drive)
 static int pdc202xx_config_drive_xfer_rate (ide_drive_t *drive)
 {
 	ide_hwif_t *hwif	= HWIF(drive);
-	struct hd_driveid *id	= drive->id;
 
 	drive->init_speed = 0;
 
-	if (id && (id->capability & 1) && drive->autodma) {
+	if (ide_use_dma(drive) && config_chipset_for_dma(drive))
+		return hwif->ide_dma_on(drive);
 
-		if (ide_use_dma(drive)) {
-			if (config_chipset_for_dma(drive))
-				return hwif->ide_dma_on(drive);
-		}
-
-		goto fast_ata_pio;
-
-	} else if ((id->capability & 8) || (id->field_valid & 2)) {
-fast_ata_pio:
+	if (ide_use_fast_pio(drive)) {
 		pdc202xx_tune_drive(drive, 255);
 		return hwif->ide_dma_off_quietly(drive);
 	}
diff --git a/drivers/ide/pci/piix.c b/drivers/ide/pci/piix.c
index 247334473519..85e8a78e10ad 100644
--- a/drivers/ide/pci/piix.c
+++ b/drivers/ide/pci/piix.c
@@ -387,19 +387,13 @@ static int piix_config_drive_for_dma (ide_drive_t *drive)
 static int piix_config_drive_xfer_rate (ide_drive_t *drive)
 {
 	ide_hwif_t *hwif	= HWIF(drive);
-	struct hd_driveid *id	= drive->id;
 
 	drive->init_speed = 0;
 
-	if ((id->capability & 1) && drive->autodma) {
+	if (ide_use_dma(drive) && piix_config_drive_for_dma(drive))
+		return hwif->ide_dma_on(drive);
 
-		if (ide_use_dma(drive) && piix_config_drive_for_dma(drive))
-			return hwif->ide_dma_on(drive);
-
-		goto fast_ata_pio;
-
-	} else if ((id->capability & 8) || (id->field_valid & 2)) {
-fast_ata_pio:
+	if (ide_use_fast_pio(drive)) {
 		/* Find best PIO mode. */
 		(void) hwif->speedproc(drive, XFER_PIO_0 +
 				       ide_get_best_pio_mode(drive, 255, 4, NULL));
diff --git a/drivers/ide/pci/serverworks.c b/drivers/ide/pci/serverworks.c
index 81a0742c4594..9e92e7ba0227 100644
--- a/drivers/ide/pci/serverworks.c
+++ b/drivers/ide/pci/serverworks.c
@@ -316,21 +316,13 @@ static int config_chipset_for_dma (ide_drive_t *drive)
 static int svwks_config_drive_xfer_rate (ide_drive_t *drive)
 {
 	ide_hwif_t *hwif	= HWIF(drive);
-	struct hd_driveid *id	= drive->id;
 
 	drive->init_speed = 0;
 
-	if ((id->capability & 1) && drive->autodma) {
+	if (ide_use_dma(drive) && config_chipset_for_dma(drive))
+		return hwif->ide_dma_on(drive);
 
-		if (ide_use_dma(drive)) {
-			if (config_chipset_for_dma(drive))
-				return hwif->ide_dma_on(drive);
-		}
-
-		goto fast_ata_pio;
-
-	} else if ((id->capability & 8) || (id->field_valid & 2)) {
-fast_ata_pio:
+	if (ide_use_fast_pio(drive)) {
 		config_chipset_for_pio(drive);
 		//	hwif->tuneproc(drive, 5);
 		return hwif->ide_dma_off_quietly(drive);
diff --git a/drivers/ide/pci/siimage.c b/drivers/ide/pci/siimage.c
index ad98510026a5..367733c8c1de 100644
--- a/drivers/ide/pci/siimage.c
+++ b/drivers/ide/pci/siimage.c
@@ -415,19 +415,11 @@ static int config_chipset_for_dma (ide_drive_t *drive)
 static int siimage_config_drive_for_dma (ide_drive_t *drive)
 {
 	ide_hwif_t *hwif	= HWIF(drive);
-	struct hd_driveid *id	= drive->id;
 
-	if ((id->capability & 1) != 0 && drive->autodma) {
+	if (ide_use_dma(drive) && config_chipset_for_dma(drive))
+		return hwif->ide_dma_on(drive);
 
-		if (ide_use_dma(drive)) {
-			if (config_chipset_for_dma(drive))
-				return hwif->ide_dma_on(drive);
-		}
-
-		goto fast_ata_pio;
-
-	} else if ((id->capability & 8) || (id->field_valid & 2)) {
-fast_ata_pio:
+	if (ide_use_fast_pio(drive)) {
 		config_chipset_for_pio(drive, 1);
 		return hwif->ide_dma_off_quietly(drive);
 	}
diff --git a/drivers/ide/pci/sis5513.c b/drivers/ide/pci/sis5513.c
index e71552e64ae4..4fff663a6432 100644
--- a/drivers/ide/pci/sis5513.c
+++ b/drivers/ide/pci/sis5513.c
@@ -670,23 +670,15 @@ static int config_chipset_for_dma (ide_drive_t *drive)
 static int sis5513_config_xfer_rate(ide_drive_t *drive)
 {
 	ide_hwif_t *hwif	= HWIF(drive);
-	struct hd_driveid *id	= drive->id;
 
 	config_art_rwp_pio(drive, 5);
 
 	drive->init_speed = 0;
 
-	if (id && (id->capability & 1) && drive->autodma) {
+	if (ide_use_dma(drive) && config_chipset_for_dma(drive))
+		return hwif->ide_dma_on(drive);
 
-		if (ide_use_dma(drive)) {
-			if (config_chipset_for_dma(drive))
-				return hwif->ide_dma_on(drive);
-		}
-
-		goto fast_ata_pio;
-
-	} else if ((id->capability & 8) || (id->field_valid & 2)) {
-fast_ata_pio:
+	if (ide_use_fast_pio(drive)) {
 		sis5513_tune_drive(drive, 5);
 		return hwif->ide_dma_off_quietly(drive);
 	}
diff --git a/drivers/ide/pci/slc90e66.c b/drivers/ide/pci/slc90e66.c
index 2663ddbd9b67..4042fd8e2308 100644
--- a/drivers/ide/pci/slc90e66.c
+++ b/drivers/ide/pci/slc90e66.c
@@ -180,19 +180,13 @@ static int slc90e66_config_drive_for_dma (ide_drive_t *drive)
 static int slc90e66_config_drive_xfer_rate (ide_drive_t *drive)
 {
 	ide_hwif_t *hwif	= HWIF(drive);
-	struct hd_driveid *id	= drive->id;
 
 	drive->init_speed = 0;
 
-	if ((id->capability & 1) && drive->autodma) {
+	if (ide_use_dma(drive) && slc90e66_config_drive_for_dma(drive))
+		return hwif->ide_dma_on(drive);
 
-		if (ide_use_dma(drive) && slc90e66_config_drive_for_dma(drive))
-			return hwif->ide_dma_on(drive);
-
-		goto fast_ata_pio;
-
-	} else if ((id->capability & 8) || (id->field_valid & 2)) {
-fast_ata_pio:
+	if (ide_use_fast_pio(drive)) {
 		(void) hwif->speedproc(drive, XFER_PIO_0 +
 				       ide_get_best_pio_mode(drive, 255, 4, NULL));
 		return hwif->ide_dma_off_quietly(drive);
diff --git a/drivers/ide/pci/tc86c001.c b/drivers/ide/pci/tc86c001.c
index 2ad72bbda342..4e893808f063 100644
--- a/drivers/ide/pci/tc86c001.c
+++ b/drivers/ide/pci/tc86c001.c
@@ -186,17 +186,11 @@ static int config_chipset_for_dma(ide_drive_t *drive)
 static int tc86c001_config_drive_xfer_rate(ide_drive_t *drive)
 {
 	ide_hwif_t *hwif	= HWIF(drive);
-	struct hd_driveid *id	= drive->id;
 
-	if ((id->capability & 1) && drive->autodma) {
+	if (ide_use_dma(drive) && config_chipset_for_dma(drive))
+		return hwif->ide_dma_on(drive);
 
-		if (ide_use_dma(drive) && config_chipset_for_dma(drive))
-			return hwif->ide_dma_on(drive);
-
-		goto fast_ata_pio;
-
-	} else if ((id->capability & 8) || (id->field_valid & 2)) {
-fast_ata_pio:
+	if (ide_use_fast_pio(drive)) {
 		tc86c001_tune_drive(drive, 255);
 		return hwif->ide_dma_off_quietly(drive);
 	}
diff --git a/drivers/ide/pci/triflex.c b/drivers/ide/pci/triflex.c
index b0d29cd7123a..1f5f6759fef8 100644
--- a/drivers/ide/pci/triflex.c
+++ b/drivers/ide/pci/triflex.c
@@ -114,14 +114,9 @@ static int triflex_config_drive_for_dma(ide_drive_t *drive)
 static int triflex_config_drive_xfer_rate(ide_drive_t *drive)
 {
 	ide_hwif_t *hwif	= HWIF(drive);
-	struct hd_driveid *id	= drive->id;
 
-	if ((id->capability & 1) && drive->autodma) {
-		if (ide_use_dma(drive)) {
-			if (triflex_config_drive_for_dma(drive))
-				return hwif->ide_dma_on(drive);
-		}
-	}
+	if (ide_use_dma(drive) && triflex_config_drive_for_dma(drive))
+		return hwif->ide_dma_on(drive);
 
 	hwif->tuneproc(drive, 255);
 	return hwif->ide_dma_off_quietly(drive);
diff --git a/drivers/ide/ppc/scc_pata.c b/drivers/ide/ppc/scc_pata.c
index 65ad8ab34598..0ab26ea5a35a 100644
--- a/drivers/ide/ppc/scc_pata.c
+++ b/drivers/ide/ppc/scc_pata.c
@@ -383,16 +383,11 @@ static int scc_config_chipset_for_dma(ide_drive_t *drive)
 static int scc_config_drive_for_dma(ide_drive_t *drive)
 {
 	ide_hwif_t *hwif = HWIF(drive);
-	struct hd_driveid *id = drive->id;
 
-	if ((id->capability & 1) != 0 && drive->autodma) {
-		if (ide_use_dma(drive)) {
-			if (scc_config_chipset_for_dma(drive))
-				return hwif->ide_dma_on(drive);
-		}
-		goto fast_ata_pio;
-	} else if ((id->capability & 8) || (id->field_valid & 2)) {
-	fast_ata_pio:
+	if (ide_use_dma(drive) && scc_config_chipset_for_dma(drive))
+		return hwif->ide_dma_on(drive);
+
+	if (ide_use_fast_pio(drive)) {
 		hwif->tuneproc(drive, 4);
 		hwif->ide_dma_off_quietly(drive);
 	}
diff --git a/include/linux/ide.h b/include/linux/ide.h
index 40b5fa2f2627..9e1a8b9ce182 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -1352,6 +1352,7 @@ extern int ide_dma_enable(ide_drive_t *drive);
 extern char *ide_xfer_verbose(u8 xfer_rate);
 extern void ide_toggle_bounce(ide_drive_t *drive, int on);
 extern int ide_set_xfer_rate(ide_drive_t *drive, u8 rate);
+int ide_use_fast_pio(ide_drive_t *);
 
 u8 ide_dump_status(ide_drive_t *, const char *, u8);