swh:1:snp:173f8deb0c56c557784b4fd217e7608ac6197844
Tip revision: 805a6af8dba5dfdd35ec35dc52ec0122400b2610 authored by Linus Torvalds on 04 January 2012, 23:55:44 UTC
Linux 3.2
Linux 3.2
Tip revision: 805a6af
fixup.c
/*
* Exceptions for specific devices. Usually work-arounds for fatal design flaws.
* Derived from fixup.c of i386 tree.
*/
#include <linux/pci.h>
#include <linux/init.h>
#include <asm/machvec.h>
/*
* Fixup to mark boot BIOS video selected by BIOS before it changes
*
* From information provided by "Jon Smirl" <jonsmirl@gmail.com>
*
* The standard boot ROM sequence for an x86 machine uses the BIOS
* to select an initial video card for boot display. This boot video
* card will have it's BIOS copied to C0000 in system RAM.
* IORESOURCE_ROM_SHADOW is used to associate the boot video
* card with this copy. On laptops this copy has to be used since
* the main ROM may be compressed or combined with another image.
* See pci_map_rom() for use of this flag. IORESOURCE_ROM_SHADOW
* is marked here since the boot video device will be the only enabled
* video device at this point.
*/
static void __devinit pci_fixup_video(struct pci_dev *pdev)
{
struct pci_dev *bridge;
struct pci_bus *bus;
u16 config;
if ((strcmp(platform_name, "dig") != 0)
&& (strcmp(platform_name, "hpzx1") != 0))
return;
/* Maybe, this machine supports legacy memory map. */
if ((pdev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
return;
/* Is VGA routed to us? */
bus = pdev->bus;
while (bus) {
bridge = bus->self;
/*
* From information provided by
* "David Miller" <davem@davemloft.net>
* The bridge control register is valid for PCI header
* type BRIDGE, or CARDBUS. Host to PCI controllers use
* PCI header type NORMAL.
*/
if (bridge
&&((bridge->hdr_type == PCI_HEADER_TYPE_BRIDGE)
||(bridge->hdr_type == PCI_HEADER_TYPE_CARDBUS))) {
pci_read_config_word(bridge, PCI_BRIDGE_CONTROL,
&config);
if (!(config & PCI_BRIDGE_CTL_VGA))
return;
}
bus = bus->parent;
}
pci_read_config_word(pdev, PCI_COMMAND, &config);
if (config & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) {
pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_SHADOW;
dev_printk(KERN_DEBUG, &pdev->dev, "Boot video device\n");
}
}
DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, pci_fixup_video);