From 321ab6a5fab812658626aee6bce2617f8cfb3a55 Mon Sep 17 00:00:00 2001 From: Lennert Buytenhek Date: Sat, 25 Jun 2005 19:30:04 +0100 Subject: [PATCH] ARM: 2752/1: disable ixp2000 PCI I/O software workaround on chips that don't need it Patch from Lennert Buytenhek The later ixp2000 models don't need the PCI I/O workaround that we currently perform. Add a config option to disable the workaround, and panic on boot if a kernel without the workaround is booted on a buggy chip. As only pre-production ixp2000s need the workaround, the default is for it not to be configured in. Signed-off-by: Lennert Buytenhek Signed-off-by: Deepak Saxena Signed-off-by: Russell King --- arch/arm/mach-ixp2000/Kconfig | 8 ++++++++ arch/arm/mach-ixp2000/pci.c | 13 +++++++++++++ 2 files changed, 21 insertions(+) (limited to 'arch/arm/mach-ixp2000') diff --git a/arch/arm/mach-ixp2000/Kconfig b/arch/arm/mach-ixp2000/Kconfig index 9361e05f6fa3..ecb58d83478e 100644 --- a/arch/arm/mach-ixp2000/Kconfig +++ b/arch/arm/mach-ixp2000/Kconfig @@ -54,6 +54,14 @@ config ARCH_IXDP2X01 depends on ARCH_IXDP2401 || ARCH_IXDP2801 default y +config IXP2000_SUPPORT_BROKEN_PCI_IO + bool "Support broken PCI I/O on older IXP2000s" + default y + help + Say 'N' here if you only intend to run your kernel on an + IXP2000 B0 or later model and do not need the PCI I/O + byteswap workaround. Say 'Y' otherwise. + endmenu endif diff --git a/arch/arm/mach-ixp2000/pci.c b/arch/arm/mach-ixp2000/pci.c index 5ff2f2718c58..0788fb2b5c10 100644 --- a/arch/arm/mach-ixp2000/pci.c +++ b/arch/arm/mach-ixp2000/pci.c @@ -198,6 +198,19 @@ clear_master_aborts(void) void __init ixp2000_pci_preinit(void) { +#ifndef CONFIG_IXP2000_SUPPORT_BROKEN_PCI_IO + /* + * Configure the PCI unit to properly byteswap I/O transactions, + * and verify that it worked. + */ + ixp2000_reg_write(IXP2000_PCI_CONTROL, + (*IXP2000_PCI_CONTROL | PCI_CONTROL_IEE)); + + if ((*IXP2000_PCI_CONTROL & PCI_CONTROL_IEE) == 0) + panic("IXP2000: PCI I/O is broken on this ixp model, and " + "the needed workaround has not been configured in"); +#endif + hook_fault_code(16+6, ixp2000_pci_abort_handler, SIGBUS, "PCI config cycle to non-existent device"); } -- cgit v1.2.3-59-g8ed1b