diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/aoe/mkshelf.sh | 6 | ||||
| -rw-r--r-- | Documentation/cciss.txt | 4 | ||||
| -rw-r--r-- | Documentation/connector/cn_test.c | 194 | ||||
| -rw-r--r-- | Documentation/connector/connector.txt | 133 | ||||
| -rw-r--r-- | Documentation/dontdiff | 1 | ||||
| -rw-r--r-- | Documentation/fb/intel810.txt | 56 | ||||
| -rw-r--r-- | Documentation/feature-removal-schedule.txt | 9 | ||||
| -rw-r--r-- | Documentation/firmware_class/firmware_sample_driver.c | 8 | ||||
| -rw-r--r-- | Documentation/input/appletouch.txt | 84 | ||||
| -rw-r--r-- | Documentation/kdump/kdump.txt | 11 | ||||
| -rw-r--r-- | Documentation/kernel-parameters.txt | 9 | ||||
| -rw-r--r-- | Documentation/oops-tracing.txt | 25 | ||||
| -rw-r--r-- | Documentation/pm.txt | 6 | ||||
| -rw-r--r-- | Documentation/scsi/00-INDEX | 2 | ||||
| -rw-r--r-- | Documentation/scsi/scsi_eh.txt | 479 | ||||
| -rw-r--r-- | Documentation/usb/proc_usb_info.txt | 13 | ||||
| -rw-r--r-- | Documentation/x86_64/boot-options.txt | 5 |
17 files changed, 987 insertions, 58 deletions
diff --git a/Documentation/aoe/mkshelf.sh b/Documentation/aoe/mkshelf.sh index 8bacf9f2c7cc..32615814271c 100644 --- a/Documentation/aoe/mkshelf.sh +++ b/Documentation/aoe/mkshelf.sh @@ -8,13 +8,15 @@ fi n_partitions=${n_partitions:-16} dir=$1 shelf=$2 +nslots=16 +maxslot=`echo $nslots 1 - p | dc` MAJOR=152 set -e -minor=`echo 10 \* $shelf \* $n_partitions | bc` +minor=`echo $nslots \* $shelf \* $n_partitions | bc` endp=`echo $n_partitions - 1 | bc` -for slot in `seq 0 9`; do +for slot in `seq 0 $maxslot`; do for part in `seq 0 $endp`; do name=e$shelf.$slot test "$part" != "0" && name=${name}p$part diff --git a/Documentation/cciss.txt b/Documentation/cciss.txt index c8f9a73111da..68a711fb82cf 100644 --- a/Documentation/cciss.txt +++ b/Documentation/cciss.txt @@ -17,7 +17,9 @@ This driver is known to work with the following cards: * SA P600 * SA P800 * SA E400 - * SA E300 + * SA P400i + * SA E200 + * SA E200i If nodes are not already created in the /dev/cciss directory, run as root: diff --git a/Documentation/connector/cn_test.c b/Documentation/connector/cn_test.c new file mode 100644 index 000000000000..b7de82e9c0e0 --- /dev/null +++ b/Documentation/connector/cn_test.c @@ -0,0 +1,194 @@ +/* + * cn_test.c + * + * 2004-2005 Copyright (c) Evgeniy Polyakov <johnpol@2ka.mipt.ru> + * All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/skbuff.h> +#include <linux/timer.h> + +#include "connector.h" + +static struct cb_id cn_test_id = { 0x123, 0x456 }; +static char cn_test_name[] = "cn_test"; +static struct sock *nls; +static struct timer_list cn_test_timer; + +void cn_test_callback(void *data) +{ + struct cn_msg *msg = (struct cn_msg *)data; + + printk("%s: %lu: idx=%x, val=%x, seq=%u, ack=%u, len=%d: %s.\n", + __func__, jiffies, msg->id.idx, msg->id.val, + msg->seq, msg->ack, msg->len, (char *)msg->data); +} + +static int cn_test_want_notify(void) +{ + struct cn_ctl_msg *ctl; + struct cn_notify_req *req; + struct cn_msg *msg = NULL; + int size, size0; + struct sk_buff *skb; + struct nlmsghdr *nlh; + u32 group = 1; + + size0 = sizeof(*msg) + sizeof(*ctl) + 3 * sizeof(*req); + + size = NLMSG_SPACE(size0); + + skb = alloc_skb(size, GFP_ATOMIC); + if (!skb) { + printk(KERN_ERR "Failed to allocate new skb with size=%u.\n", + size); + + return -ENOMEM; + } + + nlh = NLMSG_PUT(skb, 0, 0x123, NLMSG_DONE, size - sizeof(*nlh)); + + msg = (struct cn_msg *)NLMSG_DATA(nlh); + + memset(msg, 0, size0); + + msg->id.idx = -1; + msg->id.val = -1; + msg->seq = 0x123; + msg->ack = 0x345; + msg->len = size0 - sizeof(*msg); + + ctl = (struct cn_ctl_msg *)(msg + 1); + + ctl->idx_notify_num = 1; + ctl->val_notify_num = 2; + ctl->group = group; + ctl->len = msg->len - sizeof(*ctl); + + req = (struct cn_notify_req *)(ctl + 1); + + /* + * Idx. + */ + req->first = cn_test_id.idx; + req->range = 10; + + /* + * Val 0. + */ + req++; + req->first = cn_test_id.val; + req->range = 10; + + /* + * Val 1. + */ + req++; + req->first = cn_test_id.val + 20; + req->range = 10; + + NETLINK_CB(skb).dst_groups = ctl->group; + //netlink_broadcast(nls, skb, 0, ctl->group, GFP_ATOMIC); + netlink_unicast(nls, skb, 0, 0); + + printk(KERN_INFO "Request was sent. Group=0x%x.\n", ctl->group); + + return 0; + +nlmsg_failure: + printk(KERN_ERR "Failed to send %u.%u\n", msg->seq, msg->ack); + kfree_skb(skb); + return -EINVAL; +} + +static u32 cn_test_timer_counter; +static void cn_test_timer_func(unsigned long __data) +{ + struct cn_msg *m; + char data[32]; + + m = kmalloc(sizeof(*m) + sizeof(data), GFP_ATOMIC); + if (m) { + memset(m, 0, sizeof(*m) + sizeof(data)); + + memcpy(&m->id, &cn_test_id, sizeof(m->id)); + m->seq = cn_test_timer_counter; + m->len = sizeof(data); + + m->len = + scnprintf(data, sizeof(data), "counter = %u", + cn_test_timer_counter) + 1; + + memcpy(m + 1, data, m->len); + + cn_netlink_send(m, 0, gfp_any()); + kfree(m); + } + + cn_test_timer_counter++; + + mod_timer(&cn_test_timer, jiffies + HZ); +} + +static int cn_test_init(void) +{ + int err; + + err = cn_add_callback(&cn_test_id, cn_test_name, cn_test_callback); + if (err) + goto err_out; + cn_test_id.val++; + err = cn_add_callback(&cn_test_id, cn_test_name, cn_test_callback); + if (err) { + cn_del_callback(&cn_test_id); + goto err_out; + } + + init_timer(&cn_test_timer); + cn_test_timer.function = cn_test_timer_func; + cn_test_timer.expires = jiffies + HZ; + cn_test_timer.data = 0; + add_timer(&cn_test_timer); + + return 0; + + err_out: + if (nls && nls->sk_socket) + sock_release(nls->sk_socket); + + return err; +} + +static void cn_test_fini(void) +{ + del_timer_sync(&cn_test_timer); + cn_del_callback(&cn_test_id); + cn_test_id.val--; + cn_del_callback(&cn_test_id); + if (nls && nls->sk_socket) + sock_release(nls->sk_socket); +} + +module_init(cn_test_init); +module_exit(cn_test_fini); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>"); +MODULE_DESCRIPTION("Connector's test module"); diff --git a/Documentation/connector/connector.txt b/Documentation/connector/connector.txt new file mode 100644 index 000000000000..54a0a14bfbe3 --- /dev/null +++ b/Documentation/connector/connector.txt @@ -0,0 +1,133 @@ +/*****************************************/ +Kernel Connector. +/*****************************************/ + +Kernel connector - new netlink based userspace <-> kernel space easy +to use communication module. + +Connector driver adds possibility to connect various agents using +netlink based network. One must register callback and +identifier. When driver receives special netlink message with +appropriate identifier, appropriate callback will be called. + +From the userspace point of view it's quite straightforward: + + socket(); + bind(); + send(); + recv(); + +But if kernelspace want to use full power of such connections, driver +writer must create special sockets, must know about struct sk_buff +handling... Connector allows any kernelspace agents to use netlink +based networking for inter-process communication in a significantly +easier way: + +int cn_add_callback(struct cb_id *id, char *name, void (*callback) (void *)); +void cn_netlink_send(struct cn_msg *msg, u32 __group, int gfp_mask); + +struct cb_id +{ + __u32 idx; + __u32 val; +}; + +idx and val are unique identifiers which must be registered in +connector.h for in-kernel usage. void (*callback) (void *) - is a +callback function which will be called when message with above idx.val +will be received by connector core. Argument for that function must +be dereferenced to struct cn_msg *. + +struct cn_msg +{ + struct cb_id id; + + __u32 seq; + __u32 ack; + + __u32 len; /* Length of the following data */ + __u8 data[0]; +}; + +/*****************************************/ +Connector interfaces. +/*****************************************/ + +int cn_add_callback(struct cb_id *id, char *name, void (*callback) (void *)); + +Registers new callback with connector core. + +struct cb_id *id - unique connector's user identifier. + It must be registered in connector.h for legal in-kernel users. +char *name - connector's callback symbolic name. +void (*callback) (void *) - connector's callback. + Argument must be dereferenced to struct cn_msg *. + +void cn_del_callback(struct cb_id *id); + +Unregisters new callback with connector core. + +struct cb_id *id - unique connector's user identifier. + +void cn_netlink_send(struct cn_msg *msg, u32 __groups, int gfp_mask); + +Sends message to the specified groups. It can be safely called from +any context, but may silently fail under strong memory pressure. + +struct cn_msg * - message header(with attached data). +u32 __group - destination group. + If __group is zero, then appropriate group will + be searched through all registered connector users, + and message will be delivered to the group which was + created for user with the same ID as in msg. + If __group is not zero, then message will be delivered + to the specified group. +int gfp_mask - GFP mask. + +Note: When registering new callback user, connector core assigns +netlink group to the user which is equal to it's id.idx. + +/*****************************************/ +Protocol description. +/*****************************************/ + +Current offers transport layer with fixed header. Recommended +protocol which uses such header is following: + +msg->seq and msg->ack are used to determine message genealogy. When +someone sends message it puts there locally unique sequence and random +acknowledge numbers. Sequence number may be copied into +nlmsghdr->nlmsg_seq too. + +Sequence number is incremented with each message to be sent. + +If we expect reply to our message, then sequence number in received +message MUST be the same as in original message, and acknowledge +number MUST be the same + 1. + +If we receive message and it's sequence number is not equal to one we +are expecting, then it is new message. If we receive message and it's +sequence number is the same as one we are expecting, but it's +acknowledge is not equal acknowledge number in original message + 1, +then it is new message. + +Obviously, protocol header contains above id. + +connector allows event notification in the following form: kernel +driver or userspace process can ask connector to notify it when +selected id's will be turned on or off(registered or unregistered it's +callback). It is done by sending special command to connector +driver(it also registers itself with id={-1, -1}). + +As example of usage Documentation/connector now contains cn_test.c - +testing module which uses connector to request notification and to +send messages. + +/*****************************************/ +Reliability. +/*****************************************/ + +Netlink itself is not reliable protocol, that means that messages can +be lost due to memory pressure or process' receiving queue overflowed, +so caller is warned must be prepared. That is why struct cn_msg [main +connector's message header] contains u32 seq and u32 ack fields. diff --git a/Documentation/dontdiff b/Documentation/dontdiff index 96bea278bbf6..24adfe9af3ca 100644 --- a/Documentation/dontdiff +++ b/Documentation/dontdiff @@ -55,6 +55,7 @@ aic7*seq.h* aicasm aicdb.h* asm +asm-offsets.* asm_offsets.* autoconf.h* bbootsect diff --git a/Documentation/fb/intel810.txt b/Documentation/fb/intel810.txt index fd68b162e4a1..4f0d6bc789ef 100644 --- a/Documentation/fb/intel810.txt +++ b/Documentation/fb/intel810.txt @@ -5,6 +5,7 @@ Intel 810/815 Framebuffer driver March 17, 2002 First Released: July 2001 + Last Update: September 12, 2005 ================================================================ A. Introduction @@ -44,6 +45,8 @@ B. Features - Hardware Cursor Support + - Supports EDID probing either by DDC/I2C or through the BIOS + C. List of available options a. "video=i810fb" @@ -52,14 +55,17 @@ C. List of available options Recommendation: required b. "xres:<value>" - select horizontal resolution in pixels + select horizontal resolution in pixels. (This parameter will be + ignored if 'mode_option' is specified. See 'o' below). Recommendation: user preference (default = 640) c. "yres:<value>" select vertical resolution in scanlines. If Discrete Video Timings - is enabled, this will be ignored and computed as 3*xres/4. + is enabled, this will be ignored and computed as 3*xres/4. (This + parameter will be ignored if 'mode_option' is specified. See 'o' + below) Recommendation: user preference (default = 480) @@ -86,7 +92,8 @@ C. List of available options g. "hsync1/hsync2:<value>" select the minimum and maximum Horizontal Sync Frequency of the monitor in KHz. If a using a fixed frequency monitor, hsync1 must - be equal to hsync2. + be equal to hsync2. If EDID probing is successful, these will be + ignored and values will be taken from the EDID block. Recommendation: check monitor manual for correct values default (29/30) @@ -94,7 +101,8 @@ C. List of available options h. "vsync1/vsync2:<value>" select the minimum and maximum Vertical Sync Frequency of the monitor in Hz. You can also use this option to lock your monitor's refresh - rate. + rate. If EDID probing is successful, these will be ignored and values + will be taken from the EDID block. Recommendation: check monitor manual for correct values (default = 60/60) @@ -154,7 +162,11 @@ C. List of available options Recommendation: do not set (default = not set) - + o. <xres>x<yres>[-<bpp>][@<refresh>] + The driver will now accept specification of boot mode option. If this + is specified, the options 'xres' and 'yres' will be ignored. See + Documentation/fb/modedb.txt for usage. + D. Kernel booting Separate each option/option-pair by commas (,) and the option from its value @@ -176,7 +188,10 @@ will be computed based on the hsync1/hsync2 and vsync1/vsync2 values. IMPORTANT: You must include hsync1, hsync2, vsync1 and vsync2 to enable video modes -better than 640x480 at 60Hz. +better than 640x480 at 60Hz. HOWEVER, if your chipset/display combination +supports I2C and has an EDID block, you can safely exclude hsync1, hsync2, +vsync1 and vsync2 parameters. These parameters will be taken from the EDID +block. E. Module options @@ -217,32 +232,21 @@ F. Setup This is required. The option is under "Character Devices" d. Under "Graphics Support", select "Intel 810/815" either statically - or as a module. Choose "use VESA GTF for video timings" if you - need to maximize the capability of your display. To be on the + or as a module. Choose "use VESA Generalized Timing Formula" if + you need to maximize the capability of your display. To be on the safe side, you can leave this unselected. - e. If you want a framebuffer console, enable it under "Console + e. If you want support for DDC/I2C probing (Plug and Play Displays), + set 'Enable DDC Support' to 'y'. To make this option appear, set + 'use VESA Generalized Timing Formula' to 'y'. + + f. If you want a framebuffer console, enable it under "Console Drivers" - f. Compile your kernel. + g. Compile your kernel. - g. Load the driver as described in section D and E. + h. Load the driver as described in section D and E. - Optional: - h. If you are going to run XFree86 with its native drivers, the - standard XFree86 4.1.0 and 4.2.0 drivers should work as is. - However, there's a bug in the XFree86 i810 drivers. It attempts - to use XAA even when switched to the console. This will crash - your server. I have a fix at this site: - - http://i810fb.sourceforge.net. - - You can either use the patch, or just replace - - /usr/X11R6/lib/modules/drivers/i810_drv.o - - with the one provided at the website. - i. Try the DirectFB (http://www.directfb.org) + the i810 gfxdriver patch to see the chipset in action (or inaction :-). diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index 784e08c1c80a..b67189a8d8d4 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -17,15 +17,6 @@ Who: Greg Kroah-Hartman <greg@kroah.com> --------------------------- -What: io_remap_page_range() (macro or function) -When: September 2005 -Why: Replaced by io_remap_pfn_range() which allows more memory space - addressabilty (by using a pfn) and supports sparc & sparc64 - iospace as part of the pfn. -Who: Randy Dunlap <rddunlap@osdl.org> - ---------------------------- - What: RAW driver (CONFIG_RAW_DRIVER) When: December 2005 Why: declared obsolete since kernel 2.6.3 diff --git a/Documentation/firmware_class/firmware_sample_driver.c b/Documentation/firmware_class/firmware_sample_driver.c index e1c56a7e6583..4bef8c25172c 100644 --- a/Documentation/firmware_class/firmware_sample_driver.c +++ b/Documentation/firmware_class/firmware_sample_driver.c @@ -32,14 +32,14 @@ static void sample_firmware_load(char *firmware, int size) u8 buf[size+1]; memcpy(buf, firmware, size); buf[size] = '\0'; - printk("firmware_sample_driver: firmware: %s\n", buf); + printk(KERN_INFO "firmware_sample_driver: firmware: %s\n", buf); } static void sample_probe_default(void) { /* uses the default method to get the firmware */ const struct firmware *fw_entry; - printk("firmware_sample_driver: a ghost device got inserted :)\n"); + printk(KERN_INFO "firmware_sample_driver: a ghost device got inserted :)\n"); if(request_firmware(&fw_entry, "sample_driver_fw", &ghost_device)!=0) { @@ -61,7 +61,7 @@ static void sample_probe_specific(void) /* NOTE: This currently doesn't work */ - printk("firmware_sample_driver: a ghost device got inserted :)\n"); + printk(KERN_INFO "firmware_sample_driver: a ghost device got inserted :)\n"); if(request_firmware(NULL, "sample_driver_fw", &ghost_device)!=0) { @@ -83,7 +83,7 @@ static void sample_probe_async_cont(const struct firmware *fw, void *context) return; } - printk("firmware_sample_driver: device pointer \"%s\"\n", + printk(KERN_INFO "firmware_sample_driver: device pointer \"%s\"\n", (char *)context); sample_firmware_load(fw->data, fw->size); } diff --git a/Documentation/input/appletouch.txt b/Documentation/input/appletouch.txt new file mode 100644 index 000000000000..b48d11d0326d --- /dev/null +++ b/Documentation/input/appletouch.txt @@ -0,0 +1,84 @@ +Apple Touchpad Driver (appletouch) +---------------------------------- + Copyright (C) 2005 Stelian Pop <stelian@popies.net> + +appletouch is a Linux kernel driver for the USB touchpad found on post +February 2005 Apple Alu Powerbooks. + +This driver is derived from Johannes Berg's appletrackpad driver[1], but it has +been improved in some areas: + * appletouch is a full kernel driver, no userspace program is necessary + * appletouch can be interfaced with the synaptics X11 driver, in order + to have touchpad acceleration, scrolling, etc. + +Credits go to Johannes Berg for reverse-engineering the touchpad protocol, +Frank Arnold for further improvements, and Alex Harper for some additional +information about the inner workings of the touchpad sensors. + +Usage: +------ + +In order to use the touchpad in the basic mode, compile the driver and load +the module. A new input device will be detected and you will be able to read +the mouse data from /dev/input/mice (using gpm, or X11). + +In X11, you can configure the touchpad to use the synaptics X11 driver, which +will give additional functionalities, like acceleration, scrolling, 2 finger +tap for middle button mouse emulation, 3 finger tap for right button mouse +emulation, etc. In order to do this, make sure you're using a recent version of +the synaptics driver (tested with 0.14.2, available from [2]), and configure a +new input device in your X11 configuration file (take a look below for an +example). For additional configuration, see the synaptics driver documentation. + + Section "InputDevice" + Identifier "Synaptics Touchpad" + Driver "synaptics" + Option "SendCoreEvents" "true" + Option "Device" "/dev/input/mice" + Option "Protocol" "auto-dev" + Option "LeftEdge" "0" + Option "RightEdge" "850" + Option "TopEdge" "0" + Option "BottomEdge" "645" + Option "MinSpeed" "0.4" + Option "MaxSpeed" "1" + Option "AccelFactor" "0.02" + Option "FingerLow" "0" + Option "FingerHigh" "30" + Option "MaxTapMove" "20" + Option "MaxTapTime" "100" + Option "HorizScrollDelta" "0" + Option "VertScrollDelta" "30" + Option "SHMConfig" "on" + EndSection + + Section "ServerLayout" + ... + InputDevice "Mouse" + InputDevice "Synaptics Touchpad" + ... + EndSection + +Fuzz problems: +-------------- + +The touchpad sensors are very sensitive to heat, and will generate a lot of +noise when the temperature changes. This is especially true when you power-on +the laptop for the first time. + +The appletouch driver tries to handle this noise and auto adapt itself, but it +is not perfect. If finger movements are not recognized anymore, try reloading +the driver. + +You can activate debugging using the 'debug' module parameter. A value of 0 +deactivates any debugging, 1 activates tracing of invalid samples, 2 activates +full tracing (each sample is being traced): + modprobe appletouch debug=1 + or + echo "1" > /sys/module/appletouch/parameters/debug + +Links: +------ + +[1]: http://johannes.sipsolutions.net/PowerBook/touchpad/ +[2]: http://web.telia.com/~u89404340/touchpad/index.html diff --git a/Documentation/kdump/kdump.txt b/Documentation/kdump/kdump.txt index 1f5f7d28c9e6..5f08f9ce6046 100644 --- a/Documentation/kdump/kdump.txt +++ b/Documentation/kdump/kdump.txt @@ -66,11 +66,11 @@ SETUP c) Enable "/proc/vmcore support" (Optional, in Pseudo filesystems). CONFIG_PROC_VMCORE=y d) Disable SMP support and build a UP kernel (Until it is fixed). - CONFIG_SMP=n + CONFIG_SMP=n e) Enable "Local APIC support on uniprocessors". - CONFIG_X86_UP_APIC=y + CONFIG_X86_UP_APIC=y f) Enable "IO-APIC support on uniprocessors" - CONFIG_X86_UP_IOAPIC=y + CONFIG_X86_UP_IOAPIC=y Note: i) Options a) and b) depend upon "Configure standard kernel features (for small systems)" (under General setup). @@ -95,6 +95,11 @@ SETUP hence have memory less than 4GB. iii) Specify "irqpoll" as command line parameter. This reduces driver initialization failures in second kernel due to shared interrupts. + iv) <root-dev> needs to be specified in a format corresponding to + the root device name in the output of mount command. + v) If you have built the drivers required to mount root file + system as modules in <second-kernel>, then, specify + --initrd=<initrd-for-second-kernel>. 5) System reboots into the second kernel when a panic occurs. A module can be written to force the panic or "ALT-SysRq-c" can be used initiate a crash diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index db2603ceabba..7086f0a90d14 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -164,6 +164,15 @@ running once the system is up. over-ride platform specific driver. See also Documentation/acpi-hotkey.txt. + enable_timer_pin_1 [i386,x86-64] + Enable PIN 1 of APIC timer + Can be useful to work around chipset bugs (in particular on some ATI chipsets) + The kernel tries to set a reasonable default. + + disable_timer_pin_1 [i386,x86-64] + Disable PIN 1 of APIC timer + Can be useful to work around chipset bugs. + ad1816= [HW,OSS] Format: <io>,<irq>,<dma>,<dma2> See also Documentation/sound/oss/AD1816. diff --git a/Documentation/oops-tracing.txt b/Documentation/oops-tracing.txt index da711028e5f7..66eaaab7773d 100644 --- a/Documentation/oops-tracing.txt +++ b/Documentation/oops-tracing.txt @@ -205,8 +205,8 @@ Phone: 701-234-7556 Tainted kernels: Some oops reports contain the string 'Tainted: ' after the program -counter, this indicates that the kernel has been tainted by some -mechanism. The string is followed by a series of position sensitive +counter. This indicates that the kernel has been tainted by some +mechanism. The string is followed by a series of position-sensitive characters, each representing a particular tainted value. 1: 'G' if all modules loaded have a GPL or compatible license, 'P' if @@ -214,16 +214,25 @@ characters, each representing a particular tainted value. MODULE_LICENSE or with a MODULE_LICENSE that is not recognised by insmod as GPL compatible are assumed to be proprietary. - 2: 'F' if any module was force loaded by insmod -f, ' ' if all + 2: 'F' if any module was force loaded by "insmod -f", ' ' if all modules were loaded normally. 3: 'S' if the oops occurred on an SMP kernel running on hardware that - hasn't been certified as safe to run multiprocessor. - Currently this occurs only on various Athlons that are not - SMP capable. + hasn't been certified as safe to run multiprocessor. + Currently this occurs only on various Athlons that are not + SMP capable. + + 4: 'R' if a module was force unloaded by "rmmod -f", ' ' if all + modules were unloaded normally. + + 5: 'M' if any processor has reported a Machine Check Exception, + ' ' if no Machine Check Exceptions have occurred. + + 6: 'B' if a page-release function has found a bad page reference or + some unexpected page flags. The primary reason for the 'Tainted: ' string is to tell kernel debuggers if this is a clean kernel or if anything unusual has -occurred. Tainting is permanent, even if an offending module is -unloading the tainted value remains to indicate that the kernel is not +occurred. Tainting is permanent: even if an offending module is +unloaded, the tainted value remains to indicate that the kernel is not trustworthy. diff --git a/Documentation/pm.txt b/Documentation/pm.txt index cc63ae18d147..2ea1149bf6b0 100644 --- a/Documentation/pm.txt +++ b/Documentation/pm.txt @@ -38,6 +38,12 @@ system the associated daemon will exit gracefully. Driver Interface -- OBSOLETE, DO NOT USE! ----------------************************* + +Note: pm_register(), pm_access(), pm_dev_idle() and friends are +obsolete. Please do not use them. Instead you should properly hook +your driver into the driver model, and use its suspend()/resume() +callbacks to do this kind of stuff. + If you are writing a new driver or maintaining an old driver, it should include power management support. Without power management support, a single driver may prevent a system with power management diff --git a/Documentation/scsi/00-INDEX b/Documentation/scsi/00-INDEX index f9cb5bdcce41..fef92ebf266f 100644 --- a/Documentation/scsi/00-INDEX +++ b/Documentation/scsi/00-INDEX @@ -60,6 +60,8 @@ scsi.txt - short blurb on using SCSI support as a module. scsi_mid_low_api.txt - info on API between SCSI layer and low level drivers +scsi_eh.txt + - info on SCSI midlayer error handling infrastructure st.txt - info on scsi tape driver sym53c500_cs.txt diff --git a/Documentation/scsi/scsi_eh.txt b/Documentation/scsi/scsi_eh.txt new file mode 100644 index 000000000000..534a50922a7b --- /dev/null +++ b/Documentation/scsi/scsi_eh.txt @@ -0,0 +1,479 @@ + +SCSI EH +====================================== + + This document describes SCSI midlayer error handling infrastructure. +Please refer to Documentation/scsi/scsi_mid_low_api.txt for more +information regarding SCSI midlayer. + +TABLE OF CONTENTS + +[1] How SCSI commands travel through the midlayer and to EH + [1-1] struct scsi_cmnd + [1-2] How do scmd's get completed? + [1-2-1] Completing a scmd w/ scsi_done + [1-2-2] Completing a scmd w/ timeout + [1-3] How EH takes over +[2] How SCSI EH works + [2-1] EH through fine-grained callbacks + [2-1-1] Overview + [2-1-2] Flow of scmds through EH + [2-1-3] Flow of control + [2-2] EH through hostt->eh_strategy_handler() + [2-2-1] Pre hostt->eh_strategy_handler() SCSI midlayer conditions + [2-2-2] Post hostt->eh_strategy_handler() SCSI midlayer conditions + [2-2-3] Things to consider + + +[1] How SCSI commands travel through the midlayer and to EH + +[1-1] struct scsi_cmnd + + Each SCSI command is represented with struct scsi_cmnd (== scmd). A +scmd has two list_head's to link itself into lists. The two are +scmd->list and scmd->eh_entry. The former is used for free list or +per-device allocated scmd list and not of much interest to this EH +discussion. The latter is used for completion and EH lists and unless +otherwise stated scmds are always linked using scmd->eh_entry in this +discussion. + + +[1-2] How do scmd's get completed? + + Once LLDD gets hold of a scmd, either the LLDD will complete the +command by calling scsi_done callback passed from midlayer when +invoking hostt->queuecommand() or SCSI midlayer will time it out. + + +[1-2-1] Completing a scmd w/ scsi_done + + For all non-EH commands, scsi_done() is the completion callback. It +does the following. + + 1. Delete timeout timer. If it fails, it means that timeout timer + has expired and is going to finish the command. Just return. + + 2. Link scmd to per-cpu scsi_done_q using scmd->en_entry + + 3. Raise SCSI_SOFTIRQ + + SCSI_SOFTIRQ handler scsi_softirq calls scsi_decide_disposition() to +determine what to do with the command. scsi_decide_disposition() +looks at the scmd->result value and sense data to determine what to do +with the command. + + - SUCCESS + scsi_finish_command() is invoked for the command. The + function does some maintenance choirs and notify completion by + calling scmd->done() callback, which, for fs requests, would + be HLD completion callback - sd:sd_rw_intr, sr:rw_intr, + st:st_intr. + + - NEEDS_RETRY + - ADD_TO_MLQUEUE + scmd is requeued to blk queue. + + - otherwise + scsi_eh_scmd_add(scmd, 0) is invoked for the command. See + [1-3] for details of this funciton. + + +[1-2-2] Completing a scmd w/ timeout + + The timeout handler is scsi_times_out(). When a timeout occurs, this +function + + 1. invokes optional hostt->eh_timedout() callback. Return value can + be one of + + - EH_HANDLED + This indicates that eh_timedout() dealt with the timeout. The + scmd is passed to __scsi_done() and thus linked into per-cpu + scsi_done_q. Normal command completion described in [1-2-1] + follows. + + - EH_RESET_TIMER + This indicates that more time is required to finish the + command. Timer is restarted. This action is counted as a + retry and only allowed scmd->allowed + 1(!) times. Once the + limit is reached, action for EH_NOT_HANDLED is taken instead. + + *NOTE* This action is racy as the LLDD could finish the scmd + after the timeout has expired but before it's added back. In + such cases, scsi_done() would think that timeout has occurred + and return without doing anything. We lose completion and the + command will time out again. + + - EH_NOT_HANDLED + This is the same as when eh_timedout() callback doesn't exist. + Step #2 is taken. + + 2. scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD) is invoked for the + command. See [1-3] for more information. + + +[1-3] How EH takes over + + scmds enter EH via scsi_eh_scmd_add(), which does the following. + + 1. Turns on scmd->eh_eflags as requested. It's 0 for error + completions and SCSI_EH_CANCEL_CMD for timeouts. + + 2. Links scmd->eh_entry to shost->eh_cmd_q + + 3. Sets SHOST_RECOVERY bit in shost->shost_state + + 4. Increments shost->host_failed + + 5. Wakes up SCSI EH thread if shost->host_busy == shost->host_failed + + As can be seen above, once any scmd is added to shost->eh_cmd_q, +SHOST_RECOVERY shost_state bit is turned on. This prevents any new +scmd to be issued from blk queue to the host; eventually, all scmds on +the host either complete normally, fail and get added to eh_cmd_q, or +time out and get added to shost->eh_cmd_q. + + If all scmds either complete or fail, the number of in-flight scmds +becomes equal to the number of failed scmds - i.e. shost->host_busy == +shost->host_failed. This wakes up SCSI EH thread. So, once woken up, +SCSI EH thread can expect that all in-flight commands have failed and +are linked on shost->eh_cmd_q. + + Note that this does not mean lower layers are quiescent. If a LLDD +completed a scmd with error status, the LLDD and lower layers are +assumed to forget about the scmd at that point. However, if a scmd +has timed out, unless hostt->eh_timedout() made lower layers forget +about the scmd, which currently no LLDD does, the command is still +active as long as lower layers are concerned and completion could +occur at any time. Of course, all such completions are ignored as the +timer has already expired. + + We'll talk about how SCSI EH takes actions to abort - make LLDD +forget about - timed out scmds later. + + +[2] How SCSI EH works + + LLDD's can implement SCSI EH actions in one of the following two +ways. + + - Fine-grained EH callbacks + LLDD can implement fine-grained EH callbacks and let SCSI + midlayer drive error handling and call appropriate callbacks. + This will be dicussed further in [2-1]. + + - eh_strategy_handler() callback + This is one big callback which should perform whole error + handling. As such, it should do all choirs SCSI midlayer + performs during recovery. This will be discussed in [2-2]. + + Once recovery is complete, SCSI EH resumes normal operation by +calling scsi_restart_operations(), which + + 1. Checks if door locking is needed and locks door. + + 2. Clears SHOST_RECOVERY shost_state bit + + 3. Wakes up waiters on shost->host_wait. This occurs if someone + calls scsi_block_when_processing_errors() on the host. + (*QUESTION* why is it needed? All operations will be blocked + anyway after it reaches blk queue.) + + 4. Kicks queues in all devices on the host in the asses + + +[2-1] EH through fine-grained callbacks + +[2-1-1] Overview + + If eh_strategy_handler() is not present, SCSI midlayer takes charge +of driving error handling. EH's goals are two - make LLDD, host and +device forget about timed out scmds and make them ready for new +commands. A scmd is said to be recovered if the scmd is forgotten by +lower layers and lower layers are ready to process or fail the scmd +again. + + To achieve these goals, EH performs recovery actions with increasing +severity. Some actions are performed by issueing SCSI commands and +others are performed by invoking one of the following fine-grained +hostt EH callbacks. Callbacks may be omitted and omitted ones are +considered to fail always. + +int (* eh_abort_handler)(struct scsi_cmnd *); +int (* eh_device_reset_handler)(struct scsi_cmnd *); +int (* eh_bus_reset_handler)(struct scsi_cmnd *); +int (* eh_host_reset_handler)(struct scsi_cmnd *); + + Higher-severity actions are taken only when lower-severity actions +cannot recover some of failed scmds. Also, note that failure of the +highest-severity action means EH failure and results in offlining of +all unrecovered devices. + + During recovery, the following rules are followed + + - Recovery actions are performed on failed scmds on the to do list, + eh_work_q. If a recovery action succeeds for a scmd, recovered + scmds are removed from eh_work_q. + + Note that single recovery action on a scmd can recover multiple + scmds. e.g. resetting a device recovers all failed scmds on the + device. + + - Higher severity actions are taken iff eh_work_q is not empty after + lower severity actions are complete. + + - EH reuses failed scmds to issue commands for recovery. For + timed-out scmds, SCSI EH ensures that LLDD forgets about a scmd + before reusing it for EH commands. + + When a scmd is recovered, the scmd is moved from eh_work_q to EH +local eh_done_q using scsi_eh_finish_cmd(). After all scmds are +recovered (eh_work_q is empty), scsi_eh_flush_done_q() is invoked to +either retry or error-finish (notify upper layer of failure) recovered +scmds. + + scmds are retried iff its sdev is still online (not offlined during +EH), REQ_FAILFAST is not set and ++scmd->retries is less than +scmd->allowed. + + +[2-1-2] Flow of scmds through EH + + 1. Error completion / time out + ACTION: scsi_eh_scmd_add() is invoked for scmd + - set scmd->eh_eflags + - add scmd to shost->eh_cmd_q + - set SHOST_RECOVERY + - shost->host_failed++ + LOCKING: shost->host_lock + + 2. EH starts + ACTION: move all scmds to EH's local eh_work_q. shost->eh_cmd_q + is cleared. + LOCKING: shost->host_lock (not strictly necessary, just for + consistency) + + 3. scmd recovered + ACTION: scsi_eh_finish_cmd() is invoked to EH-finish scmd + - shost->host_failed-- + - clear scmd->eh_eflags + - scsi_setup_cmd_retry() + - move from local eh_work_q to local eh_done_q + LOCKING: none + + 4. EH completes + ACTION: scsi_eh_flush_done_q() retries scmds or notifies upper + layer of failure. + - scmd is removed from eh_done_q and scmd->eh_entry is cleared + - if retry is necessary, scmd is requeued using + scsi_queue_insert() + - otherwise, scsi_finish_command() is invoked for scmd + LOCKING: queue or finish function performs appropriate locking + + +[2-1-3] Flow of control + + EH through fine-grained callbacks start from scsi_unjam_host(). + +<<scsi_unjam_host>> + + 1. Lock shost->host_lock, splice_init shost->eh_cmd_q into local + eh_work_q and unlock host_lock. Note that shost->eh_cmd_q is + cleared by this action. + + 2. Invoke scsi_eh_get_sense. + + <<scsi_eh_get_sense>> + + This action is taken for each error-completed + (!SCSI_EH_CANCEL_CMD) commands without valid sense data. Most + SCSI transports/LLDDs automatically acquire sense data on + command failures (autosense). Autosense is recommended for + performance reasons and as sense information could get out of + sync inbetween occurrence of CHECK CONDITION and this action. + + Note that if autosense is not supported, scmd->sense_buffer + contains invalid sense data when error-completing the scmd + with scsi_done(). scsi_decide_disposition() always returns + FAILED in such cases thus invoking SCSI EH. When the scmd + reaches here, sense data is acquired and + scsi_decide_disposition() is called again. + + 1. Invoke scsi_request_sense() which issues REQUEST_SENSE + command. If fails, no action. Note that taking no action + causes higher-severity recovery to be taken for the scmd. + + 2. Invoke scsi_decide_disposition() on the scmd + + - SUCCESS + scmd->retries is set to scmd->allowed preventing + scsi_eh_flush_done_q() from retrying the scmd and + scsi_eh_finish_cmd() is invoked. + + - NEEDS_RETRY + scsi_eh_finish_cmd() invoked + + - otherwise + No action. + + 3. If !list_empty(&eh_work_q), invoke scsi_eh_abort_cmds(). + + <<scsi_eh_abort_cmds>> + + This action is taken for each timed out command. + hostt->eh_abort_handler() is invoked for each scmd. The + handler returns SUCCESS if it has succeeded to make LLDD and + all related hardware forget about the scmd. + + If a timedout scmd is successfully aborted and the sdev is + either offline or ready, scsi_eh_finish_cmd() is invoked for + the scmd. Otherwise, the scmd is left in eh_work_q for + higher-severity actions. + + Note that both offline and ready status mean that the sdev is + ready to process new scmds, where processing also implies + immediate failing; thus, if a sdev is in one of the two + states, no further recovery action is needed. + + Device readiness is tested using scsi_eh_tur() which issues + TEST_UNIT_READY command. Note that the scmd must have been + aborted successfully before reusing it for TEST_UNIT_READY. + + 4. If !list_empty(&eh_work_q), invoke scsi_eh_ready_devs() + + <<scsi_eh_ready_devs>> + + This function takes four increasingly more severe measures to + make failed sdevs ready for new commands. + + 1. Invoke scsi_eh_stu() + + <<scsi_eh_stu>> + + For each sdev which has failed scmds with valid sense data + of which scsi_check_sense()'s verdict is FAILED, + START_STOP_UNIT command is issued w/ start=1. Note that + as we explicitly choose error-completed scmds, it is known + that lower layers have forgotten about the scmd and we can + reuse it for STU. + + If STU succeeds and the sdev is either offline or ready, + all failed scmds on the sdev are EH-finished with + scsi_eh_finish_cmd(). + + *NOTE* If hostt->eh_abort_handler() isn't implemented or + failed, we may still have timed out scmds at this point + and STU doesn't make lower layers forget about those + scmds. Yet, this function EH-finish all scmds on the sdev + if STU succeeds leaving lower layers in an inconsistent + state. It seems that STU action should be taken only when + a sdev has no timed out scmd. + + 2. If !list_empty(&eh_work_q), invoke scsi_eh_bus_device_reset(). + + <<scsi_eh_bus_device_reset>> + + This action is very similar to scsi_eh_stu() except that, + instead of issuing STU, hostt->eh_device_reset_handler() + is used. Also, as we're not issuing SCSI commands and + resetting clears all scmds on the sdev, there is no need + to choose error-completed scmds. + + 3. If !list_empty(&eh_work_q), invoke scsi_eh_bus_reset() + + <<scsi_eh_bus_reset>> + + hostt->eh_bus_reset_handler() is invoked for each channel + with failed scmds. If bus reset succeeds, all failed + scmds on all ready or offline sdevs on the channel are + EH-finished. + + 4. If !list_empty(&eh_work_q), invoke scsi_eh_host_reset() + + <<scsi_eh_host_reset>> + + This is the last resort. hostt->eh_host_reset_handler() + is invoked. If host reset succeeds, all failed scmds on + all ready or offline sdevs on the host are EH-finished. + + 5. If !list_empty(&eh_work_q), invoke scsi_eh_offline_sdevs() + + <<scsi_eh_offline_sdevs>> + + Take all sdevs which still have unrecovered scmds offline + and EH-finish the scmds. + + 5. Invoke scsi_eh_flush_done_q(). + + <<scsi_eh_flush_done_q>> + + At this point all scmds are recovered (or given up) and + put on eh_done_q by scsi_eh_finish_cmd(). This function + flushes eh_done_q by either retrying or notifying upper + layer of failure of the scmds. + + +[2-2] EH through hostt->eh_strategy_handler() + + hostt->eh_strategy_handler() is invoked in the place of +scsi_unjam_host() and it is responsible for whole recovery process. +On completion, the handler should have made lower layers forget about +all failed scmds and either ready for new commands or offline. Also, +it should perform SCSI EH maintenance choirs to maintain integrity of +SCSI midlayer. IOW, of the steps described in [2-1-2], all steps +except for #1 must be implemented by eh_strategy_handler(). + + +[2-2-1] Pre hostt->eh_strategy_handler() SCSI midlayer conditions + + The following conditions are true on entry to the handler. + + - Each failed scmd's eh_flags field is set appropriately. + + - Each failed scmd is linked on scmd->eh_cmd_q by scmd->eh_entry. + + - SHOST_RECOVERY is set. + + - shost->host_failed == shost->host_busy + + +[2-2-2] Post hostt->eh_strategy_handler() SCSI midlayer conditions + + The following conditions must be true on exit from the handler. + + - shost->host_failed is zero. + + - Each scmd's eh_eflags field is cleared. + + - Each scmd is in such a state that scsi_setup_cmd_retry() on the + scmd doesn't make any difference. + + - shost->eh_cmd_q is cleared. + + - Each scmd->eh_entry is cleared. + + - Either scsi_queue_insert() or scsi_finish_command() is called on + each scmd. Note that the handler is free to use scmd->retries and + ->allowed to limit the number of retries. + + +[2-2-3] Things to consider + + - Know that timed out scmds are still active on lower layers. Make + lower layers forget about them before doing anything else with + those scmds. + + - For consistency, when accessing/modifying shost data structure, + grab shost->host_lock. + + - On completion, each failed sdev must have forgotten about all + active scmds. + + - On completion, each failed sdev must be ready for new commands or + offline. + + +-- +Tejun Heo +htejun@gmail.com +11th September 2005 diff --git a/Documentation/usb/proc_usb_info.txt b/Documentation/usb/proc_usb_info.txt index 729c72d34c89..f86550fe38ee 100644 --- a/Documentation/usb/proc_usb_info.txt +++ b/Documentation/usb/proc_usb_info.txt @@ -20,7 +20,7 @@ the /proc/bus/usb/BBB/DDD files. to /etc/fstab. This will mount usbfs at each reboot. You can then issue `cat /proc/bus/usb/devices` to extract - USB device information, and user mode drivers can use usbfs + USB device information, and user mode drivers can use usbfs to interact with USB devices. There are a number of mount options supported by usbfs. @@ -32,7 +32,7 @@ the /proc/bus/usb/BBB/DDD files. still see references to the older "usbdevfs" name. For more information on mounting the usbfs file system, see the -"USB Device Filesystem" section of the USB Guide. The latest copy +"USB Device Filesystem" section of the USB Guide. The latest copy of the USB Guide can be found at http://www.linux-usb.org/ @@ -133,7 +133,7 @@ B: Alloc=ddd/ddd us (xx%), #Int=ddd, #Iso=ddd are the only transfers that reserve bandwidth. Control and bulk transfers use all other bandwidth, including reserved bandwidth that is not used for transfers (such as for short packets). - + The percentage is how much of the "reserved" bandwidth is scheduled by those transfers. For a low or full speed bus (loosely, "USB 1.1"), 90% of the bus bandwidth is reserved. For a high speed bus (loosely, @@ -197,7 +197,7 @@ C:* #Ifs=dd Cfg#=dd Atr=xx MPwr=dddmA | | |__NumberOfInterfaces | |__ "*" indicates the active configuration (others are " ") |__Config info tag - + USB devices may have multiple configurations, each of which act rather differently. For example, a bus-powered configuration might be much less capable than one that is self-powered. Only @@ -228,7 +228,7 @@ I: If#=dd Alt=dd #EPs=dd Cls=xx(sssss) Sub=xx Prot=xx Driver=ssss For example, default settings may not use more than a small amount of periodic bandwidth. To use significant fractions of bus bandwidth, drivers must select a non-default altsetting. - + Only one setting for an interface may be active at a time, and only one driver may bind to an interface at a time. Most devices have only one alternate setting per interface. @@ -297,18 +297,21 @@ S: SerialNumber=dce0 C:* #Ifs= 1 Cfg#= 1 Atr=40 MxPwr= 0mA I: If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub E: Ad=81(I) Atr=03(Int.) MxPS= 8 Ivl=255ms + T: Bus=00 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 2 Spd=12 MxCh= 4 D: Ver= 1.00 Cls=09(hub ) Sub=00 Prot=00 MxPS= 8 #Cfgs= 1 P: Vendor=0451 ProdID=1446 Rev= 1.00 C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=100mA I: If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub E: Ad=81(I) Atr=03(Int.) MxPS= 1 Ivl=255ms + T: Bus=00 Lev=02 Prnt=02 Port=00 Cnt=01 Dev#= 3 Spd=1.5 MxCh= 0 D: Ver= 1.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 8 #Cfgs= 1 P: Vendor=04b4 ProdID=0001 Rev= 0.00 C:* #Ifs= 1 Cfg#= 1 Atr=80 MxPwr=100mA I: If#= 0 Alt= 0 #EPs= 1 Cls=03(HID ) Sub=01 Prot=02 Driver=mouse E: Ad=81(I) Atr=03(Int.) MxPS= 3 Ivl= 10ms + T: Bus=00 Lev=02 Prnt=02 Port=02 Cnt=02 Dev#= 4 Spd=12 MxCh= 0 D: Ver= 1.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 8 #Cfgs= 1 P: Vendor=0565 ProdID=0001 Rev= 1.08 diff --git a/Documentation/x86_64/boot-options.txt b/Documentation/x86_64/boot-options.txt index 678e8f192db2..ffe1c062088b 100644 --- a/Documentation/x86_64/boot-options.txt +++ b/Documentation/x86_64/boot-options.txt @@ -11,6 +11,11 @@ Machine check If your BIOS doesn't do that it's a good idea to enable though to make sure you log even machine check events that result in a reboot. + mce=tolerancelevel (number) + 0: always panic, 1: panic if deadlock possible, + 2: try to avoid panic, 3: never panic or exit (for testing) + default is 1 + Can be also set using sysfs which is preferable. nomce (for compatibility with i386): same as mce=off |