From 57d4810ea0d9ca58a7bcc1336607f0cede0a2abf Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Tue, 31 Jul 2007 00:38:02 -0700 Subject: [PATCH] revert "x86, serial: convert legacy COM ports to platform devices" MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Revert 7e92b4fc345f5b6f57585fbe5ffdb0f24d7c9b26. It broke Sébastien Dugué's machine and Jeff said (persuasively) This seems like it will break decades-long-working stuff, in favor of breaking new ground in our favorite area, "trusting the BIOS." It's just not worth it for serial ports, IMO. Serial ports are something that just shouldn't break at this late stage in the game. My new Intel platform boxes don't even have serial ports, so I question the value of messing with serial port probing even more... because... just wait a year, and your box won't have a serial port either! :) I certainly don't object to the use of platform devices (or isa_driver), but the probe change seems questionable. That's sorta analagous to rewriting the floppy driver probe routine. Sure you could do it... but why risk all that damage and go through debugging all over again? It seems clear from this report that we cannot, should not, trust BIOS for something (a) so simple and (b) that has been working for over a decade. Much discussion ensued and we've decided to have another go at all of this. Cc: Sébastien Dugué Cc: Bjorn Helgaas Cc: Len Brown Cc: Adam Belay Cc: Matthew Garrett Cc: Russell King Cc: Jeff Garzik Acked-by: Alan Cox Cc: Michal Piotrowski Cc: Sascha Sommer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/kernel-parameters.txt | 5 --- arch/i386/kernel/Makefile | 1 - arch/i386/kernel/legacy_serial.c | 67 ----------------------------- arch/x86_64/kernel/Makefile | 2 - drivers/serial/Kconfig | 14 +++--- include/asm-i386/serial.h | 16 +++++++ include/asm-x86_64/serial.h | 16 +++++++ 7 files changed, 37 insertions(+), 84 deletions(-) delete mode 100644 arch/i386/kernel/legacy_serial.c diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index d763ebe11afe..efdb42fd3fb8 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -864,11 +864,6 @@ 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:,irq: - legacy_serial.force [HW,X86-32,X86-64] - Probe for COM ports at legacy addresses even - if PNPBIOS or ACPI should describe them. This - is for working around firmware defects. - load_ramdisk= [RAM] List of ramdisks to load from floppy See Documentation/ramdisk.txt. diff --git a/arch/i386/kernel/Makefile b/arch/i386/kernel/Makefile index dbe5e87e0d66..9d33b00de659 100644 --- a/arch/i386/kernel/Makefile +++ b/arch/i386/kernel/Makefile @@ -35,7 +35,6 @@ 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 deleted file mode 100644 index 21510118544e..000000000000 --- a/arch/i386/kernel/legacy_serial.c +++ /dev/null @@ -1,67 +0,0 @@ -/* - * 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 - * - * 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 -#include -#include -#include - -/* 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 d1d18c1ea0f4..ff5d8c9b96d9 100644 --- a/arch/x86_64/kernel/Makefile +++ b/arch/x86_64/kernel/Makefile @@ -32,7 +32,6 @@ 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 @@ -51,7 +50,6 @@ 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 18f629706448..819fc3efc468 100644 --- a/drivers/serial/Kconfig +++ b/drivers/serial/Kconfig @@ -88,21 +88,17 @@ config SERIAL_8250_PCI depends on SERIAL_8250 && PCI default SERIAL_8250 help - 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. + This builds standard PCI serial support. You may be able to + disable this feature if you only need legacy serial support. + Saves about 9K. config SERIAL_8250_PNP tristate "8250/16550 PNP device support" if EMBEDDED depends on SERIAL_8250 && PNP default SERIAL_8250 help - 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. + This builds standard PNP serial support. You may be able to + disable this feature if you only need legacy serial support. config SERIAL_8250_HP300 tristate diff --git a/include/asm-i386/serial.h b/include/asm-i386/serial.h index 57a4306cdf63..bd67480ca109 100644 --- a/include/asm-i386/serial.h +++ b/include/asm-i386/serial.h @@ -11,3 +11,19 @@ * 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 8ebd765c674a..b0496e0d72a6 100644 --- a/include/asm-x86_64/serial.h +++ b/include/asm-x86_64/serial.h @@ -11,3 +11,19 @@ * 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 */