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authorLennert Buytenhek <buytenh@wantstofly.org>2005-06-25 22:30:04 +0400
committerRussell King <rmk+kernel@arm.linux.org.uk>2005-06-25 22:30:04 +0400
commit321ab6a5fab812658626aee6bce2617f8cfb3a55 (patch)
tree4e8d828a52bba4c3ab30413f51eedbb50c86b7c5 /arch/arm/mach-ixp2000
parent3cd9e19ebc91593c9f076410d6f979be188f01a0 (diff)
downloadlinux-321ab6a5fab812658626aee6bce2617f8cfb3a55.tar.xz
[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 <buytenh@wantstofly.org> Signed-off-by: Deepak Saxena Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mach-ixp2000')
-rw-r--r--arch/arm/mach-ixp2000/Kconfig8
-rw-r--r--arch/arm/mach-ixp2000/pci.c13
2 files changed, 21 insertions, 0 deletions
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");
}