Re: [PATCH 2.6.18] IA64: Add pci_fixup_video into IA64 kernel for embedded VGA

From: Bjorn Helgaas
Date: Tue Sep 26 2006 - 11:10:32 EST


On Tuesday 26 September 2006 01:42, eiichiro.oiwa.nm@xxxxxxxxxxx wrote:
> To be compatible with Xorg's handling of PCI, we need pci_fixup_video on IA64
> platform like x86 platform. There are also machines, which have VGA embedded
> into main board, among IA64 platform. Embedded VGA generally don't have PCI ROM,
> and there are VGA ROM image in System BIOS. Therefore, these machines need
> pci_fixup_video for the sysfs rom. pci_fixup_video already exists in x86 Linux
> kernel. However since this function doesn't exist in IA64 kernel, we could not
> run X server on IA64 box has embedded-VGA.
>
> I tested pci_fixup_video on IA64 box has embedded-VGA. I confirmed we can read
> VGA BIOS from the sysfs rom regardless of embedded-VGA.

What other architectures will need this? There's nothing ia64-specific
in the patch below. Can it be put somewhere more generic?

> diff -dupNr linux-2.6.18.orig/arch/ia64/pci/Makefile linux-2.6.18/arch/ia64/pci/Makefile
> --- linux-2.6.18.orig/arch/ia64/pci/Makefile 2006-09-20 12:42:06.000000000 +0900
> +++ linux-2.6.18/arch/ia64/pci/Makefile 2006-09-25 18:36:50.000000000 +0900
> @@ -1,4 +1,4 @@
> #
> # Makefile for the ia64-specific parts of the pci bus
> #
> -obj-y := pci.o
> +obj-y := pci.o fixup.o
> diff -dupNr linux-2.6.18.orig/arch/ia64/pci/fixup.c linux-2.6.18/arch/ia64/pci/fixup.c
> --- linux-2.6.18.orig/arch/ia64/pci/fixup.c 1970-01-01 09:00:00.000000000 +0900
> +++ linux-2.6.18/arch/ia64/pci/fixup.c 2006-09-25 18:35:12.000000000 +0900
> @@ -0,0 +1,56 @@
> +/*
> + * Exceptions for specific devices. Usually work-arounds for fatal design flaws.
> + *
> + * Derived from fixup.c of i386 tree.
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/dmi.h>
> +#include <linux/pci.h>
> +#include <linux/init.h>
> +
> +
> +/*
> + * Fixup to mark boot BIOS video selected by BIOS before it changes
> + *
> + * From information provided by "Jon Smirl" <jonsmirl@xxxxxxxxx>
> + *
> + * 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 ((pdev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
> + return;
> +
> + /* Is VGA routed to us? */
> + bus = pdev->bus;
> + while (bus) {
> + bridge = bus->self;
> + if (bridge) {
> + 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;
> + printk(KERN_DEBUG "Boot video device is %s\n", pci_name(pdev));
> + }
> +}
> +DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, pci_fixup_video);
>
> -
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