Tejun Heo [Fri, 6 Jan 2006 08:57:31 +0000 (09:57 +0100)]
[BLOCK] update IDE to use new blk_ordered for barriers
Update IDE to use new blk_ordered. This change makes the
following behavior changes.
* Partial completion of the barrier request is handled as
failure of the whole ordered sequence. No more partial
completion for barrier requests.
* Any failure of pre or post flush request results in failure
of the whole ordered sequence.
So, successfully completed ordered sequence guarantees that
all requests prior to the barrier made to physical medium and,
then, the while barrier request made to the physical medium.
Tejun Heo [Fri, 6 Jan 2006 08:52:55 +0000 (09:52 +0100)]
[BLOCK] update SCSI to use new blk_ordered for barriers
All ordered request related stuff delegated to HLD. Midlayer
now doens't deal with ordered setting or prepare_flush
callback. sd.c updated to deal with blk_queue_ordered
setting. Currently, ordered tag isn't used as SCSI midlayer
cannot guarantee request ordering.
Tejun Heo [Fri, 6 Jan 2006 08:51:03 +0000 (09:51 +0100)]
[BLOCK] reimplement handling of barrier request
Reimplement handling of barrier requests.
* Flexible handling to deal with various capabilities of
target devices.
* Retry support for falling back.
* Tagged queues which don't support ordered tag can do ordered.
Tejun Heo [Fri, 6 Jan 2006 08:49:03 +0000 (09:49 +0100)]
[BLOCK] add @uptodate to end_that_request_last() and @error to rq_end_io_fn()
add @uptodate argument to end_that_request_last() and @error
to rq_end_io_fn(). there's no generic way to pass error code
to request completion function, making generic error handling
of non-fs request difficult (rq->errors is driver-specific and
each driver uses it differently). this patch adds @uptodate
to end_that_request_last() and @error to rq_end_io_fn().
for fs requests, this doesn't really matter, so just using the
same uptodate argument used in the last call to
end_that_request_first() should suffice. imho, this can also
help the generic command-carrying request jens is working on.
the patch below marks various read-only variables in block/* as const,
so that gcc can optimize the use of them; eg gcc will replace the use by
the value directly now and will even remove the memory usage of these.
Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Jens Axboe <axboe@suse.de>
Jens Axboe [Fri, 6 Jan 2006 08:43:28 +0000 (09:43 +0100)]
[BLOCK] bio: check for same page merge possibilities in __bio_add_page()
For filesystems with a blocksize < page size, we can merge same page
calls into the bio_vec at the end of the bio. This saves segments
on systems with a page size > the "normal" 4kb fs block size.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@suse.de>
Tejun Heo [Fri, 11 Nov 2005 13:27:09 +0000 (14:27 +0100)]
[BLOCK] as-iosched: update alias handling
Unlike other ioscheds, as-iosched handles alias by chaing them using
rq->queuelist. As aliased requests are very rare in the first place,
this complicates merge/dispatch handling without meaningful
performance improvement. This patch updates as-iosched to dump
aliased requests into dispatch queue as other ioscheds do.
Chuck Ebbert [Fri, 6 Jan 2006 04:11:29 +0000 (23:11 -0500)]
[PATCH] i386: PTRACE_POKEUSR: allow changing RF bit in EFLAGS register.
Setting RF (resume flag) allows a debugger to resume execution after a
code breakpoint without tripping the breakpoint again. It is reset by
the CPU after execution of one instruction.
Requested by Stephane Eranian:
"I am trying to the user HW debug registers on i386 and I am running
into a problem with ptrace() not allowing access to EFLAGS_RF for
POKEUSER (see FLAG_MASK). [ ... ] It avoids the need to remove the
breakpoint, single step, and reinstall. The equivalent functionality
exists on IA-64 and is allowed by ptrace()"
Export the stored values instead of re-reading everything in the socket
information sysfs files, and make them accessible to all users, not only
to root.
Vitaly Bordug [Thu, 8 Dec 2005 15:56:12 +0000 (13:56 -0200)]
[PATCH] 8xx PCMCIA: support for MPC885ADS and MPC866ADS
This adds PCMCIA support for both MPC885ADS and MPC866ADS.
This is established not together with FADS, because 885 does not have
io_block_mapping() for BCSR area.
Also, some cleanups done both for 885ADS and MBX.
[PATCH] pcmcia: properly handle static mem, but dynamic io sockets
Some PCMCIA sockets have statically mapped memory windows, but dynamically
mapped IO windows. Using the "nonstatic" socket library is inpractical for
them, as they do neither need a resource database (as we can trust the
kernel resource database on m68k and ppc) nor lots of other features of that
library. Let them get a small "iodyn" socket library (105 lines of code)
instead.
[PATCH] pcmcia: unify attach, EVENT_CARD_INSERTION handlers into one probe callback
Unify the EVENT_CARD_INSERTION and "attach" callbacks to one unified
probe() callback. As all in-kernel drivers are changed to this new
callback, there will be no temporary backwards-compatibility. Inside a
probe() function, each driver _must_ set struct pcmcia_device
*p_dev->instance and instance->handle correctly.
With these patches, the basic driver interface for 16-bit PCMCIA drivers
now has the classic four callbacks known also from other buses:
int (*probe) (struct pcmcia_device *dev);
void (*remove) (struct pcmcia_device *dev);
int (*suspend) (struct pcmcia_device *dev);
int (*resume) (struct pcmcia_device *dev);
Move the suspend and resume methods out of the event handler, and into
special functions. Also use these functions for pre- and post-reset, as
almost all drivers already do, and the remaining ones can easily be
converted.
Bugfix to include/pcmcia/ds.c Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Daniel Ritz [Thu, 3 Nov 2005 20:12:14 +0000 (21:12 +0100)]
[PATCH] yenta: make bridge specific init code configurable
Make the bridge specific initialization code config options depending on
CONFIG_EMBEDDED. Config options for TI/EnE, Toshiba, Ricoh and O2Micro are
available. Disabling all of the specific tweaks cuts off more than half
of yenta_socket.ko.
Signed-off-by: Daniel Ritz <daniel.ritz@gmx.ch> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Add a return value to pcmcia_validate_mem. Only if we have enough memory
available to map the CIS, we should proceed in trying to determine information
about the device.
Tony Luck [Thu, 5 Jan 2006 21:30:52 +0000 (13:30 -0800)]
[IA64] Fix compile warnings in setup.c
arch/ia64/kernel/setup.c: In function `show_cpuinfo':
arch/ia64/kernel/setup.c:576: warning: long unsigned int format, different type arg (arg 12)
arch/ia64/kernel/setup.c:576: warning: long unsigned int format, different type arg (arg 13)
Luis F. Ortiz [Thu, 5 Jan 2006 21:12:41 +0000 (13:12 -0800)]
[ATYFB]: Fix onboard video on SPARC Blade 100 for 2.6.{13,14,15}
I have recently been switching from using 2.4.32 on my trusty
old Sparc Blade 100 to using 2.6.15 . Some of the problems I ran into
were distorted video when the console was active (missing first
character, skipped dots) and when running X windows (colored snow,
stripes, missing pixels). A quick examination of the 2.6 versus 2.4
source for the ATY driver revealed alot of changes.
A closer look at the code/data for the 64GR/XL chip revealed
two minor "typos" that the rewriter(s) of the code made. The first is
a incorrect clock value (230 .vs. 235) and the second is a missing
flag (M64F_SDRAM_MAGIC_PLL). Making both these changes seems to have
fixed my problem. I tend to think the 235 value is the correct one,
as there is a 29.4 Mhz clock crystal close to the video chip and 235.2
(29.4*8) is too close to 235 to make it a coincidence.
The flag for M64F_SDRAM_MAGIC_PLL was dropped during the
changes made by adaplas in file revision 1.72 on the old bitkeeper
repository.
The change relating to the clock rate has been there forever,
at least in the 2.6 tree. I'm not sure where to look for the old 2.5
tree or if anyone cares when it happened.
On SPARC Blades 100's, which use the ATY MACH64GR video chipset, the
clock crystal frequency is 235.2 Mhz, not 230 Mhz. The chipset also
requires the use of M64F_SDRAM_MAGIC_PLL in order to setup the PLL
properly for the DRAM.
Signed-off-by: Luis F. Ortiz <lfo@Polyad.Org> Signed-off-by: David S. Miller <davem@davemloft.net>
CC [M] net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.o
net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c: In function 'ipv4_refrag':
net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c:198: error: dereferencing pointer to incomplete type
make[3]: *** [net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.o] Error 1
Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Patrick McHardy [Thu, 5 Jan 2006 20:21:16 +0000 (12:21 -0800)]
[NETFILTER]: make ipv6_find_hdr() find transport protocol header
The original ipv6_find_hdr() finds the specified header in IPv6 packets.
This makes it possible to get transport header so that we can kill similar
loop in ip6_match_packet().
Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Patrick McHardy [Thu, 5 Jan 2006 20:20:59 +0000 (12:20 -0800)]
[NETFILTER]: Call POST_ROUTING hook before fragmentation
Call POST_ROUTING hook before fragmentation to get rid of the okfn use
in ip_refrag and save the useless fragmentation/defragmentation step
when NAT is used.
The patch introduces one user-visible change, the POSTROUTING chain
in the mangle table gets entire packets, not fragments, which should
simplify use of the MARK and CLASSIFY targets for queueing as a nice
side-effect.
Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
[NETFILTER]: Filter dumped entries based on the layer 3 protocol number
Dump entries of a given Layer 3 protocol number.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Cleanup: Use 'else if' instead of a ugly 'goto' statement.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
[NETFILTER]: ctnetlink: use u_int32_t instead of unsigned int
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
[NETFILTER]: ctnetlink: propagate ctnetlink_dump_tuples_proto return value back
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
[NETFILTER]: ctnetlink: Add sanity checkings for ICMP
Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
[NETFILTER]: ctnetlink: remove bogus checks in ICMP protocol at dumping
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Jesper Juhl [Thu, 5 Jan 2006 20:16:16 +0000 (12:16 -0800)]
[NETFILTER]: Decrease number of pointer derefs in nf_conntrack_core.c
Benefits of the patch:
- Fewer pointer dereferences should make the code slightly faster.
- Size of generated code is smaller
- improved readability
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Jesper Juhl [Thu, 5 Jan 2006 20:15:58 +0000 (12:15 -0800)]
[NETFILTER]: Decrease number of pointer derefs in nfnetlink_queue.c
Benefits of the patch:
- Fewer pointer dereferences should make the code slightly faster.
- Size of generated code is smaller
- improved readability
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Adrian Bunk [Thu, 5 Jan 2006 20:14:43 +0000 (12:14 -0800)]
[IPVS]: Fix compilation
Signed-off-by: Adrian Bunk <bunk@stusta.de> Acked-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Linus Torvalds [Thu, 5 Jan 2006 00:20:40 +0000 (16:20 -0800)]
Relax the rw_verify_area() error checking.
In particular, allow over-large read- or write-requests to be downgraded
to a more reasonable range, rather than considering them outright errors.
We want to protect lower layers from (the sadly all too common) overflow
conditions, but prefer to do so by chopping the requests up, rather than
just refusing them outright.
Cc: Peter Anvin <hpa@zytor.com> Cc: Ulrich Drepper <drepper@redhat.com> Cc: Andi Kleen <ak@suse.de> Cc: Al Viro <viro@ftp.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Kay Sievers [Mon, 19 Dec 2005 00:42:56 +0000 (01:42 +0100)]
[PATCH] net: swich device attribute creation to default attrs
Recent udev versions don't longer cover bad sysfs timing with built-in
logic. Explicit rules are required to do that. For net devices, the
following is needed:
ACTION=="add", SUBSYSTEM=="net", WAIT_FOR_SYSFS="address"
to handle access to net device properties from an event handler without
races.
This patch changes the main net attributes to be created by the driver
core, which is done _before_ the event is sent out and will not require
the stat() loop of the WAIT_FOR_SYSFS key.
Signed-off-by: Kay Sievers <kay.sievers@suse.de> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
[PATCH] Driver core: Make block devices create the proper symlink name
Block devices need to add the block device name to the symlink they put
in the device directory, otherwise multiple symlinks of the same name
can be created. This matches the class system, which works the same
way, we just forgot to convert block at the same time.
Cc: Pete Zaitcev <zaitcev@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
[PATCH] Driver core: only all userspace bind/unbind if CONFIG_HOTPLUG is enabled
Thanks to drivers making their id tables __devinit, we can't allow
userspace to bind or unbind drivers from devices manually through sysfs.
So we only allow this if CONFIG_HOTPLUG is enabled.
Rusty Russell [Sat, 10 Dec 2005 11:48:20 +0000 (22:48 +1100)]
[PATCH] Input: fix add modalias support build error
Fix build when scripts/mod/file2alias.c includes linux/input.h, which
tries to include /usr/include/linux/mod_devicetable.h:
In file included from scripts/mod/file2alias.c:40:
include/linux/input.h:21:35: linux/mod_devicetable.h: No such file or directory
make[2]: *** [scripts/mod/file2alias.o] Error 1
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Rusty Russell [Wed, 7 Dec 2005 20:40:34 +0000 (21:40 +0100)]
[PATCH] Input: add modalias support
Here's the patch for modalias support for input classes. It uses
comma-separated numbers, and doesn't describe all the potential keys (no
module currently cares, and that would make the strings huge). The
changes to input.h are to move the definitions needed by file2alias
outside __KERNEL__. I chose not to move those definitions to
mod_devicetable.h, because there are so many that it might break compile
of something else in the kernel.
The rest is fairly straightforward.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> CC: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Kay Sievers [Mon, 12 Dec 2005 17:03:44 +0000 (18:03 +0100)]
[PATCH] ide: MODALIAS support for autoloading of ide-cd, ide-disk, ...
IDE: MODALIAS support for autoloading of ide-cd, ide-disk, ...
Add MODULE_ALIAS to IDE midlayer modules: ide-disk, ide-cd, ide-floppy and
ide-tape, to autoload these modules depending on the probed media type of
the IDE device.
It is used by udev and replaces the former agent shell script of the hotplug
package, which was required to lookup the media type in the proc filesystem.
Using proc was racy, cause the media file is created after the hotplug event
is sent out.
The module autoloading does not take any effect, until something like the
following udev rule is configured:
SUBSYSTEM=="ide", ACTION=="add", ENV{MODALIAS}=="?*", RUN+="/sbin/modprobe $env{MODALIAS}"
The module ide-scsi will not be autoloaded, cause it requires manual
configuration. It can't be, and never was supported for automatic setup in
the hotplug package. Adding a MODULE_ALIAS to ide-scsi for all supported
media types, would just lead to a default blacklist entry anyway.
$ modinfo ide-disk
filename: /lib/modules/2.6.15-rc4-g1b0997f5/kernel/drivers/ide/ide-disk.ko
description: ATA DISK Driver
alias: ide:*m-disk*
license: GPL
...
It also adds attributes to the IDE device:
$ tree /sys/bus/ide/devices/0.0/
/sys/bus/ide/devices/0.0/
|-- bus -> ../../../../../../../bus/ide
|-- drivename
|-- media
|-- modalias
|-- power
| |-- state
| `-- wakeup
`-- uevent
$ cat /sys/bus/ide/devices/0.0/{modalias,drivename,media}
ide:m-disk
hda
disk
Signed-off-by: Kay Sievers <kay.sievers@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
akpm@osdl.org [Wed, 23 Nov 2005 07:36:13 +0000 (23:36 -0800)]
[PATCH] kobject_uevent CONFIG_NET=n fix
lib/lib.a(kobject_uevent.o)(.text+0x25f): In function `kobject_uevent':
: undefined reference to `__alloc_skb'
lib/lib.a(kobject_uevent.o)(.text+0x2a1): In function `kobject_uevent':
: undefined reference to `skb_over_panic'
lib/lib.a(kobject_uevent.o)(.text+0x31d): In function `kobject_uevent':
: undefined reference to `skb_over_panic'
lib/lib.a(kobject_uevent.o)(.text+0x356): In function `kobject_uevent':
: undefined reference to `netlink_broadcast'
lib/lib.a(kobject_uevent.o)(.init.text+0x9): In function `kobject_uevent_init':
: undefined reference to `netlink_kernel_create'
make: *** [.tmp_vmlinux1] Error 1
Netlink is unconditionally enabled if CONFIG_NET, so that's OK.
kobject_uevent.o is compiled even if !CONFIG_HOTPLUG, which is lazy.
Let's compound the sin.
Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Kumar Gala [Mon, 28 Nov 2005 16:15:39 +0000 (10:15 -0600)]
[PATCH] Allow overlapping resources for platform devices
There are cases in which a device's memory mapped registers overlap
with another device's memory mapped registers. On several PowerPC
devices this occurs for the MDIO bus, whose registers tended to overlap
with one of the ethernet controllers.
By switching from request_resource to insert_resource we can register
the MDIO bus as a proper platform device and not hack around how we
handle its memory mapped registers.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Frank Pavlic [Sun, 27 Nov 2005 04:48:40 +0000 (20:48 -0800)]
[PATCH] klist: Fix broken kref counting in find functions
The klist reference counting in the find functions that use
klist_iter_init_node is broken. If the function (for example
driver_find_device) is called with a NULL start object then everything is
fine, the first call to next_device()/klist_next increases the ref-count of
the first node on the list and does nothing for the start object which is
NULL.
If they are called with a valid start object then klist_next will decrement
the ref-count for the start object but nobody has incremented it. Logical
place to fix this would be klist_iter_init_node because the function puts a
reference of the object into the klist_iter struct.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Frank Pavlic <pavlic@de.ibm.com> Cc: Patrick Mochel <mochel@digitalimplant.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Alan Stern [Thu, 17 Nov 2005 21:54:12 +0000 (16:54 -0500)]
[PATCH] Hold the device's parent's lock during probe and remove
This patch (as604) makes the driver core hold a device's parent's lock
as well as the device's lock during calls to the probe and remove
methods in a driver. This facility is needed by USB device drivers,
owing to the peculiar way USB devices work:
A device provides multiple interfaces, and drivers are bound
to interfaces rather than to devices;
Nevertheless a reset, reset-configuration, suspend, or resume
affects the entire device and requires the caller to hold the
lock for the device, not just a lock for one of the interfaces.
Since a USB driver's probe method is always called with the interface
lock held, the locking order rules (always lock parent before child)
prevent these methods from acquiring the device lock. The solution
provided here is to call all probe and remove methods, for all devices
(not just USB), with the parent lock already acquired.
Although currently only the USB subsystem requires these changes, people
have mentioned in prior discussion that the overhead of acquiring an
extra semaphore in all the prove/remove sequences is not overly large.
Up to now, the USB core has been using its own set of private
semaphores. A followup patch will remove them, relying entirely on the
device semaphores provided by the driver core.
The code paths affected by this patch are:
device_add and device_del: The USB core already holds the parent
lock, so no actual change is needed.
driver_register and driver_unregister: The driver core will now
lock both the parent and the device before probing or removing.
driver_bind and driver_unbind (in sysfs): These routines will
now lock both the parent and the device before binding or
unbinding.
bus_rescan_devices: The helper routine will lock the parent
before probing a device.
I have not tested this patch for conflicts with other subsystems. As
far as I can see, the only possibility of conflict would lie in the
bus_rescan_devices pathway, and it seems pretty remote. Nevertheless,
it would be good for this to get a lot of testing in -mm.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Paul Jackson [Sat, 26 Nov 2005 04:04:26 +0000 (20:04 -0800)]
[PATCH] driver kill hotplug word from sn and others fix
The first of these changes s/hotplug/uevent/ was needed to
compile sn2_defconfig (ia64/sn). The other three files
changed are blind changes of all remaining bus_type.hotplug
references I could find to bus_type.uevent.
This patch attempts to finish similar changes made in the
gregkh-driver-kill-hotplug-word-from-driver-core Nov 22 patch.
Signed-off-by: Paul Jackson <pj@sgi.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
[PATCH] HOTPLUG: always enable the .config option, unless EMBEDDED
With modules, dynamic /dev, and uevents, people really want
CONFIG_HOTPLUG to be enabled in their kernels. If not, they can still
disable it, but it is discouraged.
projects / linux-2.6 / log