[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>
diff --git a/drivers/ide/pci/piix.c b/drivers/ide/pci/piix.c
index 8ecd2d6..edb37f3 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 @@
* @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 @@
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 */