From 7e92b4fc345f5b6f57585fbe5ffdb0f24d7c9b26 Mon Sep 17 00:00:00 2001
From: Bjorn Helgaas <bjorn.helgaas@hp.com>
Date: Tue, 8 May 2007 00:36:07 -0700
Subject: x86, serial: convert legacy COM ports to platform devices

Make x86 COM ports into platform devices and don't probe for them
if we have PNP.

This prevents double discovery, where a device was found both by
the legacy probe and by 8250_pnp, e.g.,

    serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
    00:02: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A

This also means IRDA devices without a UART PNP ID will no longer be
claimed by the serial driver, which might require changes in IRDA
drivers and administration.

In addition to this patch, you may need to configure a setserial init
script, e.g., /etc/init.d/setserial, so it doesn't poke legacy UART
stuff back in.  On Debian, "dpkg-reconfigure setserial" with the "kernel"
option does this.

To force the old legacy probe behavior even when we have PNPBIOS or
ACPI, load the new legacy_serial module (or build 8250 static) with
the "legacy_serial.force" option.

[akpm@linux-foundation.org: fix makefiles]
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Keith Owens <kaos@ocs.com.au>
Cc: Len Brown <lenb@kernel.org>
Cc: Adam Belay <ambx1@neo.rr.com>
Cc: Matthieu CASTET <castet.matthieu@free.fr>
Cc: Jean Tourrilhes <jt@hpl.hp.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Ville Syrjala <syrjala@sci.fi>
Cc: Russell King <rmk+serial@arm.linux.org.uk>
Cc: Samuel Ortiz <samuel@sortiz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 arch/x86_64/kernel/Makefile | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'arch/x86_64')

diff --git a/arch/x86_64/kernel/Makefile b/arch/x86_64/kernel/Makefile
index 4d94c51803d..de1de8a2fd8 100644
--- a/arch/x86_64/kernel/Makefile
+++ b/arch/x86_64/kernel/Makefile
@@ -32,6 +32,7 @@ obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
 obj-$(CONFIG_IOMMU)		+= pci-gart.o aperture.o
 obj-$(CONFIG_CALGARY_IOMMU)	+= pci-calgary.o tce.o
 obj-$(CONFIG_SWIOTLB)		+= pci-swiotlb.o
+obj-$(CONFIG_SERIAL_8250)	+= legacy_serial.o
 obj-$(CONFIG_KPROBES)		+= kprobes.o
 obj-$(CONFIG_X86_PM_TIMER)	+= pmtimer.o
 obj-$(CONFIG_X86_VSMP)		+= vsmp.o
@@ -49,6 +50,7 @@ CFLAGS_vsyscall.o		:= $(PROFILING) -g0
 
 therm_throt-y                   += ../../i386/kernel/cpu/mcheck/therm_throt.o
 bootflag-y			+= ../../i386/kernel/bootflag.o
+legacy_serial-y			+= ../../i386/kernel/legacy_serial.o
 cpuid-$(subst m,y,$(CONFIG_X86_CPUID))  += ../../i386/kernel/cpuid.o
 topology-y                     += ../../i386/kernel/topology.o
 microcode-$(subst m,y,$(CONFIG_MICROCODE))  += ../../i386/kernel/microcode.o
-- 
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