[PATCH] PIIX/SLC90E66: PIO mode fallback fix

The fallback to PIO mode in the hwif->dma_check() handler doesn't work in
the Intel PIIX and SMsC SLC90E66 IDE drivers because:

- config_drive_for_dma() calls the hwif->speedproc() handler with a wrong
  mode number (unbiased by XFER_PIO_0) in case of the PIO fallback;

- hwif->tuneproc() handler doesn't really set the drive's own speed (this
  is not fixed as yet).

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 25 insertions, 28 deletions

diff --git a/drivers/ide/pci/piix.c b/drivers/ide/pci/piix.c
index 8ecd2d668dba..edb37f3d558d 100644
--- a/drivers/ide/pci/piix.c
+++ b/drivers/ide/pci/piix.c
@@ -1,13 +1,14 @@
 /*
- *  linux/drivers/ide/pci/piix.c        Version 0.44    March 20, 2003
+ *  linux/drivers/ide/pci/piix.c        Version 0.45    May 12, 2006
  *
  *  Copyright (C) 1998-1999 Andrzej Krzysztofowicz, Author and Maintainer
  *  Copyright (C) 1998-2000 Andre Hedrick <andre@linux-ide.org>
  *  Copyright (C) 2003 Red Hat Inc <alan@redhat.com>
+ *  Copyright (C) 2006 MontaVista Software, Inc. <source@mvista.com>
  *
  *  May be copied or modified under the terms of the GNU General Public License
  *
- *  PIO mode setting function for Intel chipsets.  
+ *  PIO mode setting function for Intel chipsets.
  *  For use instead of BIOS settings.
  *
  * 40-41
@@ -25,7 +26,7 @@
  * sitre = word42 & 0x4000; secondary
  *
  * 44 8421|8421    hdd|hdb
- * 
+ *
  * 48 8421         hdd|hdc|hdb|hda udma enabled
  *
  *    0001         hda
@@ -357,21 +358,20 @@ static int piix_tune_chipset (ide_drive_t *drive, u8 xferspeed)
  *      @drive: IDE drive to configure
  *
  *      Set up a PIIX interface channel for the best available speed.
- *      We prefer UDMA if it is available and then MWDMA. If DMA is 
- *      not available we switch to PIO and return 0. 
+ *      We prefer UDMA if it is available and then MWDMA.  If DMA is
+ *      not available we switch to PIO and return 0.
  */
  
 static int piix_config_drive_for_dma (ide_drive_t *drive)
 {
         u8 speed = ide_dma_speed(drive, piix_ratemask(drive));
 
-        /* If no DMA speed was available or the chipset has DMA bugs
-           then disable DMA and use PIO */
-           
-        if (!speed || no_piix_dma) {
-                u8 tspeed = ide_get_best_pio_mode(drive, 255, 5, NULL);
-                speed = piix_dma_2_pio(XFER_PIO_0 + tspeed);
-        }
+        /*
+         * If no DMA speed was available or the chipset has DMA bugs
+         * then disable DMA and use PIO
+         */
+        if (!speed || no_piix_dma)
+                return 0;
 
         (void) piix_tune_chipset(drive, speed);
         return ide_dma_enable(drive);
@@ -394,17 +394,16 @@ static int piix_config_drive_xfer_rate (ide_drive_t *drive)
 
         if ((id->capability & 1) && drive->autodma) {
 
-                if (ide_use_dma(drive)) {
-                        if (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:
                 /* Find best PIO mode. */
-                hwif->tuneproc(drive, 255);
+                (void) hwif->speedproc(drive, XFER_PIO_0 +
+                                       ide_get_best_pio_mode(drive, 255, 4, NULL));
                 return hwif->ide_dma_off_quietly(drive);
         }
         /* IORDY not supported */
diff --git a/drivers/ide/pci/slc90e66.c b/drivers/ide/pci/slc90e66.c
index 4a1853af3bbb..9be7e49cba0e 100644
--- a/drivers/ide/pci/slc90e66.c
+++ b/drivers/ide/pci/slc90e66.c
@@ -1,9 +1,10 @@
 /*
- *  linux/drivers/ide/pci/slc90e66.c    Version 0.11    September 11, 2002
+ *  linux/drivers/ide/pci/slc90e66.c    Version 0.12    May 12, 2006
  *
  *  Copyright (C) 2000-2002 Andre Hedrick <andre@linux-ide.org>
+ *  Copyright (C) 2006 MontaVista Software, Inc. <source@mvista.com>
  *
- * This a look-a-like variation of the ICH0 PIIX4 Ultra-66,
+ * This is a look-alike variation of the ICH0 PIIX4 Ultra-66,
  * but this keeps the ISA-Bridge and slots alive.
  *
  */
@@ -158,10 +159,8 @@ static int slc90e66_config_drive_for_dma (ide_drive_t *drive)
 {
         u8 speed = ide_dma_speed(drive, slc90e66_ratemask(drive));
 
-        if (!(speed)) {
-                u8 tspeed = ide_get_best_pio_mode(drive, 255, 5, NULL);
-                speed = slc90e66_dma_2_pio(XFER_PIO_0 + tspeed);
-        }
+        if (!speed)
+                return 0;
 
         (void) slc90e66_tune_chipset(drive, speed);
         return ide_dma_enable(drive);
@@ -176,16 +175,15 @@ static int slc90e66_config_drive_xfer_rate (ide_drive_t *drive)
 
         if (id && (id->capability & 1) && drive->autodma) {
 
-                if (ide_use_dma(drive)) {
-                        if (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:
-                hwif->tuneproc(drive, 5);
+                (void) hwif->speedproc(drive, XFER_PIO_0 +
+                                       ide_get_best_pio_mode(drive, 255, 4, NULL));
                 return hwif->ide_dma_off_quietly(drive);
         }
         /* IORDY not supported */