7 files changed, 84 insertions, 37 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index fa885174fd75..bebebe4fd469 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -816,6 +816,11 @@ and is between 256 and 4096 characters. It is defined in the file
         lasi=           [HW,SCSI] PARISC LASI driver for the 53c700 chip
                         Format: addr:<io>,irq:<irq>
 
+        legacy_serial.force [HW,IA-32,X86-64]
+                        Probe for COM ports at legacy addresses even
+                        if PNPBIOS or ACPI should describe them.  This
+                        is for working around firmware defects.
+
         llsc*=          [IA64] See function print_params() in
                         arch/ia64/sn/kernel/llsc4.c.
 
diff --git a/arch/i386/kernel/Makefile b/arch/i386/kernel/Makefile
index 4f98516b9f94..91cff8dc9e1a 100644
--- a/arch/i386/kernel/Makefile
+++ b/arch/i386/kernel/Makefile
@@ -34,6 +34,7 @@ obj-y				+= sysenter.o vsyscall.o
 obj-$(CONFIG_ACPI_SRAT)         += srat.o
 obj-$(CONFIG_EFI)               += efi.o efi_stub.o
 obj-$(CONFIG_DOUBLEFAULT)       += doublefault.o
+obj-$(CONFIG_SERIAL_8250)       += legacy_serial.o
 obj-$(CONFIG_VM86)              += vm86.o
 obj-$(CONFIG_EARLY_PRINTK)      += early_printk.o
 obj-$(CONFIG_HPET_TIMER)        += hpet.o
diff --git a/arch/i386/kernel/legacy_serial.c b/arch/i386/kernel/legacy_serial.c
new file mode 100644
index 000000000000..21510118544e
--- /dev/null
+++ b/arch/i386/kernel/legacy_serial.c
@@ -0,0 +1,67 @@
+/*
+ * Legacy COM port devices for x86 platforms without PNPBIOS or ACPI.
+ * Data taken from include/asm-i386/serial.h.
+ *
+ * (c) Copyright 2007 Hewlett-Packard Development Company, L.P.
+ *      Bjorn Helgaas <bjorn.helgaas@hp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/pnp.h>
+#include <linux/serial_8250.h>
+
+/* Standard COM flags (except for COM4, because of the 8514 problem) */
+#ifdef CONFIG_SERIAL_DETECT_IRQ
+#define COM_FLAGS (UPF_BOOT_AUTOCONF | UPF_SKIP_TEST | UPF_AUTO_IRQ)
+#define COM4_FLAGS (UPF_BOOT_AUTOCONF | UPF_AUTO_IRQ)
+#else
+#define COM_FLAGS (UPF_BOOT_AUTOCONF | UPF_SKIP_TEST)
+#define COM4_FLAGS UPF_BOOT_AUTOCONF
+#endif
+
+#define PORT(_base,_irq,_flags)                         \
+        {                                               \
+                .iobase         = _base,                \
+                .irq            = _irq,                 \
+                .uartclk        = 1843200,              \
+                .iotype         = UPIO_PORT,            \
+                .flags          = _flags,               \
+        }
+
+static struct plat_serial8250_port x86_com_data[] = {
+        PORT(0x3F8, 4, COM_FLAGS),
+        PORT(0x2F8, 3, COM_FLAGS),
+        PORT(0x3E8, 4, COM_FLAGS),
+        PORT(0x2E8, 3, COM4_FLAGS),
+        { },
+};
+
+static struct platform_device x86_com_device = {
+        .name                   = "serial8250",
+        .id                     = PLAT8250_DEV_PLATFORM,
+        .dev                    = {
+                .platform_data  = x86_com_data,
+        },
+};
+
+static int force_legacy_probe;
+module_param_named(force, force_legacy_probe, bool, 0);
+MODULE_PARM_DESC(force, "Force legacy serial port probe");
+
+static int __init serial8250_x86_com_init(void)
+{
+        if (pnp_platform_devices && !force_legacy_probe)
+                return -ENODEV;
+
+        return platform_device_register(&x86_com_device);
+}
+
+module_init(serial8250_x86_com_init);
+
+MODULE_AUTHOR("Bjorn Helgaas");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Generic 8250/16x50 legacy probe module");
diff --git a/arch/x86_64/kernel/Makefile b/arch/x86_64/kernel/Makefile
index 4d94c51803d8..de1de8a2fd84 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
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 924e9bd757f0..e8efe938c4e7 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -73,17 +73,21 @@ config SERIAL_8250_PCI
         depends on SERIAL_8250 && PCI
         default SERIAL_8250
         help
-          This builds standard PCI serial support. You may be able to
-          disable this feature if you only need legacy serial support.
-          Saves about 9K.
+          Say Y here if you have PCI serial ports.
+
+          To compile this driver as a module, choose M here: the module
+          will be called 8250_pci.
 
 config SERIAL_8250_PNP
         tristate "8250/16550 PNP device support" if EMBEDDED
         depends on SERIAL_8250 && PNP
         default SERIAL_8250
         help
-          This builds standard PNP serial support. You may be able to
-          disable this feature if you only need legacy serial support.
+          Say Y here if you have serial ports described by PNPBIOS or ACPI.
+          These are typically ports built into the system board.
+
+          To compile this driver as a module, choose M here: the module
+          will be called 8250_pnp.
 
 config SERIAL_8250_HP300
         tristate
diff --git a/include/asm-i386/serial.h b/include/asm-i386/serial.h
index bd67480ca109..57a4306cdf63 100644
--- a/include/asm-i386/serial.h
+++ b/include/asm-i386/serial.h
@@ -11,19 +11,3 @@
  * megabits/second; but this requires the faster clock.
  */
 #define BASE_BAUD ( 1843200 / 16 )
-
-/* Standard COM flags (except for COM4, because of the 8514 problem) */
-#ifdef CONFIG_SERIAL_DETECT_IRQ
-#define STD_COM_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ)
-#define STD_COM4_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_AUTO_IRQ)
-#else
-#define STD_COM_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST)
-#define STD_COM4_FLAGS ASYNC_BOOT_AUTOCONF
-#endif
-
-#define SERIAL_PORT_DFNS                        \
-        /* UART CLK   PORT IRQ     FLAGS        */                      \
-        { 0, BASE_BAUD, 0x3F8, 4, STD_COM_FLAGS },      /* ttyS0 */     \
-        { 0, BASE_BAUD, 0x2F8, 3, STD_COM_FLAGS },      /* ttyS1 */     \
-        { 0, BASE_BAUD, 0x3E8, 4, STD_COM_FLAGS },      /* ttyS2 */     \
-        { 0, BASE_BAUD, 0x2E8, 3, STD_COM4_FLAGS },     /* ttyS3 */
diff --git a/include/asm-x86_64/serial.h b/include/asm-x86_64/serial.h
index b0496e0d72a6..8ebd765c674a 100644
--- a/include/asm-x86_64/serial.h
+++ b/include/asm-x86_64/serial.h
@@ -11,19 +11,3 @@
  * megabits/second; but this requires the faster clock.
  */
 #define BASE_BAUD ( 1843200 / 16 )
-
-/* Standard COM flags (except for COM4, because of the 8514 problem) */
-#ifdef CONFIG_SERIAL_DETECT_IRQ
-#define STD_COM_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ)
-#define STD_COM4_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_AUTO_IRQ)
-#else
-#define STD_COM_FLAGS (ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST)
-#define STD_COM4_FLAGS ASYNC_BOOT_AUTOCONF
-#endif
-
-#define SERIAL_PORT_DFNS                        \
-        /* UART CLK   PORT IRQ     FLAGS        */                      \
-        { 0, BASE_BAUD, 0x3F8, 4, STD_COM_FLAGS },      /* ttyS0 */     \
-        { 0, BASE_BAUD, 0x2F8, 3, STD_COM_FLAGS },      /* ttyS1 */     \
-        { 0, BASE_BAUD, 0x3E8, 4, STD_COM_FLAGS },      /* ttyS2 */     \
-        { 0, BASE_BAUD, 0x2E8, 3, STD_COM4_FLAGS },     /* ttyS3 */