[PATCH] PIIX: remove check for broken MW DMA mode 0

[PATCH] PIIX: remove check for broken MW DMA mode 0

[Sergei Shtylyov]

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Hello.

    There's no need to check in piix_config_drive_for_dma() for broken MW DMA
mode 0 as this mode is not supported by the driver (it sets hwif->mwdma_mask
to 0x6), and hence can't be selected by ide_dma_speed().

MBR, Sergei

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>


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Index: linus/drivers/ide/pci/piix.c
===================================================================
--- linus.orig/drivers/ide/pci/piix.c
+++ linus/drivers/ide/pci/piix.c
@@ -334,33 +334,6 @@ static int piix_tune_chipset (ide_drive_
 }
 
 /**
- *	piix_faulty_dma0		-	check for DMA0 errata
- *	@hwif: IDE interface to check
- *
- *	If an ICH/ICH0/ICH2 interface is is operating in multi-word
- *	DMA mode with 600nS cycle time the IDE PIO prefetch buffer will
- *	inadvertently provide an extra piece of secondary data to the primary
- *	device resulting in data corruption.
- *
- *	With such a device this test function returns true. This allows
- *	our tuning code to follow Intel recommendations and use PIO on
- *	such devices.
- */
- 
-static int piix_faulty_dma0(ide_hwif_t *hwif)
-{
-	switch(hwif->pci_dev->device)
-	{
-		case PCI_DEVICE_ID_INTEL_82801AA_1:	/* ICH */
-		case PCI_DEVICE_ID_INTEL_82801AB_1:	/* ICH0 */
-		case PCI_DEVICE_ID_INTEL_82801BA_8:	/* ICH2 */
-		case PCI_DEVICE_ID_INTEL_82801BA_9:	/* ICH2 */
-			return 1;
-	}
-	return 0;
-}
-
-/**
  *	piix_config_drive_for_dma	-	configure drive for DMA
  *	@drive: IDE drive to configure
  *
@@ -372,10 +345,6 @@ static int piix_faulty_dma0(ide_hwif_t *
 static int piix_config_drive_for_dma (ide_drive_t *drive)
 {
 	u8 speed = ide_dma_speed(drive, piix_ratemask(drive));
-	
-	/* Some ICH devices cannot support DMA mode 0 */
-	if(speed == XFER_MW_DMA_0 && piix_faulty_dma0(HWIF(drive)))
-		speed = 0;
 
 	/*
 	 * If no DMA speed was available or the chipset has DMA bugs