path: root/drivers/pci/quirks.c

/*
 *  This file contains work-arounds for many known PCI hardware
 *  bugs.  Devices present only on certain architectures (host
 *  bridges et cetera) should be handled in arch-specific code.
 *
 *  Note: any quirks for hotpluggable devices must _NOT_ be declared __init.
 *
 *  Copyright (c) 1999 Martin Mares <mj@ucw.cz>
 *
 *  Init/reset quirks for USB host controllers should be in the
 *  USB quirks file, where their drivers can access reuse it.
 *
 *  The bridge optimization stuff has been removed. If you really
 *  have a silly BIOS which is unable to set your host bridge right,
 *  use the PowerTweak utility (see http://powertweak.sourceforge.net).
 */

#include <linux/config.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/acpi.h>
#include "pci.h"

/* Deal with broken BIOS'es that neglect to enable passive release,
   which can cause problems in combination with the 82441FX/PPro MTRRs */
static void __devinit quirk_passive_release(struct pci_dev *dev)
{
	struct pci_dev *d = NULL;
	unsigned char dlc;

	/* We have to make sure a particular bit is set in the PIIX3
	   ISA bridge, so we have to go out and find it. */
	while ((d = pci_get_device(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82371SB_0, d))) {
		pci_read_config_byte(d, 0x82, &dlc);
		if (!(dlc & 1<<1)) {
			printk(KERN_ERR "PCI: PIIX3: Enabling Passive Release on %s\n", pci_name(d));
			dlc |= 1<<1;
			pci_write_config_byte(d, 0x82, dlc);
		}
	}
}
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,	PCI_DEVICE_ID_INTEL_82441,	quirk_passive_release );

/*  The VIA VP2/VP3/MVP3 seem to have some 'features'. There may be a workaround
    but VIA don't answer queries. If you happen to have good contacts at VIA
    ask them for me please -- Alan 
    
    This appears to be BIOS not version dependent. So presumably there is a 
    chipset level fix */
int isa_dma_bridge_buggy;		/* Exported */
    
static void __devinit quirk_isa_dma_hangs(struct pci_dev *dev)
{
	if (!isa_dma_bridge_buggy) {
		isa_dma_bridge_buggy=1;
		printk(KERN_INFO "Activating ISA DMA hang workarounds.\n");
	}
}
	/*
	 * Its not totally clear which chipsets are the problematic ones
	 * We know 82C586 and 82C596 variants are affected.
	 */
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_VIA,	PCI_DEVICE_ID_VIA_82C586_0,	quirk_isa_dma_hangs );
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_VIA,	PCI_DEVICE_ID_VIA_82C596,	quirk_isa_dma_hangs );
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,    PCI_DEVICE_ID_INTEL_82371SB_0,  quirk_isa_dma_hangs );
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_AL,	PCI_DEVICE_ID_AL_M1533, 	quirk_isa_dma_hangs );
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_NEC,	PCI_DEVICE_ID_NEC_CBUS_1,	quirk_isa_dma_hangs );
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_NEC,	PCI_DEVICE_ID_NEC_CBUS_2,	quirk_isa_dma_hangs );
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_NEC,	PCI_DEVICE_ID_NEC_CBUS_3,	quirk_isa_dma_hangs );

int pci_pci_problems;

/*
 *	Chipsets where PCI->PCI transfers vanish or hang
 */
static void __devinit quirk_nopcipci(struct pci_dev *dev)
{
	if ((pci_pci_problems & PCIPCI_FAIL)==0) {
		printk(KERN_INFO "Disabling direct PCI/PCI transfers.\n");
		pci_pci_problems |= PCIPCI_FAIL;
	}
}
DECLARE_PCI_FIXUP_FINAL