The klist utility routines currently call _put methods while holding a
spinlock. This is of course illegal; a put routine could try to
unregister a device and hence need to sleep.
No problems have arisen until now because in many cases klist removals
were done synchronously, so the _put methods were never actually used.
In other cases we may simply have been lucky.
This patch (as784) reworks the klist routines so that _put methods are
called only _after_ the klist's spinlock has been released.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as783) simplifies the driver core slightly by removing four
unnecessary _get and _put methods.
It is vital that when a driver is removed from its bus's klist of
registered drivers, or when a device is removed from a driver's klist
of bound devices, that the klist updates complete synchronously.
Otherwise the kernel might try binding an unregistered driver to a
newly-registered device, or adding a device to the klist for a new
driver before it has been removed from the old driver's klist.
Since the removals must be synchronous, they don't need to update any
reference counts. Hence the _get and _put methods can be dispensed
with.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There is a potential deadlock in the driver core. It boils down to
the fact that bus_remove_device() calls klist_remove() instead of
klist_del(), thereby waiting until the reference count of the
klist_node in the bus's klist of devices drops to 0. The refcount
can't reach 0 so long as a modprobe process is trying to bind a new
driver to the device being removed, by calling __driver_attach(). The
problem is that __driver_attach() tries to acquire the device's
parent's semaphore, but the caller of bus_remove_device() is quite
likely to own that semaphore already.
It isn't sufficient just to replace klist_remove() with klist_del().
Doing so runs the risk that the device would remain on the bus's klist
of devices for some time, and so could be bound to another driver even
after it was unregistered. What's needed is a new way to distinguish
whether or not a device is registered, based on a criterion other than
whether its klist_node is linked into the bus's klist of devices. That
way driver binding can fail when the device is unregistered, even if
it is still linked into the klist.
This patch (as782) implements the solution, by adding a new bitflag to
indiate when a struct device is registered, by testing the flag before
allowing a driver to bind a device, and by changing the definition of
the device_is_registered() inline.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This provides a build and run-time option to turn on multhreaded probe
for all PCI drivers. It can cause bad problems on multi-processor
machines that take a while to find their root disks, and play havoc on
machines that don't use persistant device names for block or network
devices.
But it can cause speedups on some machines, my tiny laptop's boot goes
up by 0.4 seconds, and my desktop boots up several seconds faster.
Use at your own risk!!!
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This adds the infrastructure for drivers to do a threaded probe, and
waits at init time for all currently outstanding probes to complete.
A new kernel thread will be created when the probe() function for the
driver is called, if the multithread_probe bit is set in the driver
saying it can support this kind of operation.
I have tested this with USB and PCI, and it works, and shaves off a lot
of time in the boot process, but there are issues with finding root boot
disks, and some USB drivers assume that this can never happen, so it is
currently not enabled for any bus type. Individual drivers can enable
this right now if they wish, and bus authors can selectivly turn it on
as well, once they determine that their subsystem will work properly
with it.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Don't be crufty. Mark it __must_check too.
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The platform_notify call for Arm and PPC architectures needs to be called
before the driver attaches to the device. The problem only presents itself
when hotplugging certain devices while the driver is already loaded.
Signed-off-by: Brian Walsh <brian@walsh.ws>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We get hundreds of these:
include/media/v4l2-dev.h:348: warning: ignoring return value of 'class_device_create_file', declared with attribute warn_unused_result
Handle it, and propagate the __must_check back a level.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Those 1500 warnings can be a bit of a pain. Add a config option to shut them
up.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We're getting a lot of crashes in the sysfs/kobject/device/bus/class code and
they're very hard to diagnose.
I'm suspecting that in some cases this is because drivers aren't checking
return values and aren't handling errors correctly. So the code blithely
blunders on and crashes later in very obscure ways.
There's just no reason to ignore errors which can and do occur. So the patch
sprinkles __must_check all over these APIs.
Causes 1,513 new warnings. Heh.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When CONFIG_HOTPLUG is n, add_bind_files() definition is wrong.
This patch has fixed it.
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make sysfs_remove_bin_file() void. If it detects an error,
printk the file name and call dump_stack().
sysfs_hash_and_remove() now returns an error code indicating
its success or failure so that sysfs_remove_bin_file() can
know success/failure.
Convert the only driver that checked the return value of
sysfs_remove_bin_file().
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Makes it easier for devices to create and remove binary attribute files
so they don't have to call directly into sysfs. This is needed to help
with the conversion from struct class_device to struct device.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When moving class_device usage over to device, we need to handle
class_interfaces properly with devices. This patch adds that support.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This change creates a devices/virtual/CLASS_NAME tree for struct devices
that belong to a class, yet do not have a "real" struct device for a
parent. It automatically creates the directories on the fly as needed.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This adds two new callbacks to the class structure:
int (*dev_uevent)(struct device *dev, char **envp, int num_envp,
char *buffer, int buffer_size);
void (*dev_release)(struct device *dev);
And one pointer:
struct device_attribute * dev_attrs;
which all corrispond with the same thing as the "normal" class devices
do, yet this is for when a struct device is bound to a class.
Someday soon, struct class_device will go away, and then the other
fields in this structure can be removed too. But this is necessary in
order to get the transition to work properly.
Tested out on a network core patch that converted it to use struct
device instead of struct class_device.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This fixes an oops when a device is attached to a class, yet has no
"parent" device. An example of this would be the "lo" device in the
network core.
We should create a "virtual" subdirectory under /sys/devices/ for these,
but no one seems to agree on a proper name for it yet...
Oh, and update my copyright on the driver core.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This is needed for the network class devices in order to be able to
convert over to use struct device.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Teach platform_bus about the new suspend_late/resume_early PM calls,
issued with IRQs off. Do we really need sysdev and friends any more,
or can janitors start switching its users over to platform_device so
we can do a minor code-ectomy?
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This adds warning when someone tries them from atomic context.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The file sysfs-power that documents the interface in the /sys/power/ directory
is added to Documentation/ABI/testing.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Remove the new suspend_prepare() phase. It doesn't seem very usable,
has never been tested, doesn't address fault cleanup, and would need
a sibling resume_complete(); plus there are no real use cases. It
could be restored later if those issues get resolved.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This lists the /sys/devices/.../power/state file, and its internal support,
as due for removal next year.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add a new PM_SYSFS_DEPRECATED config option to control whether or
not the /sys/devices/.../power/state files are provided. This will
make it easier to get rid of that mechanism when the time comes,
and to verify that userspace tools work right without it.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Updates to match current code:
- Make writes to the /sys/devices/.../power/state files fail cleanly
if the device requires the irqs-off call variants.
- Fix comments describing the /sys/devices/.../power/state file writes
to match the code; the last several releases have invalidated the
previous text.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This turned into a rewrite of Documentation/power/devices.txt:
- Provide more of the "big picture"
- Fixup some of the horribly ancient/obsolete description of device suspend()
semantics; lots of text just got deleted.
- Add a decent description of PM_EVENT_* codes, including the new PRETHAW code
needed in some swsusp scenarios.
- Describe the new PM factorization from Linus:
* class suspend, current suspend, then suspend_late
* NOT suspend_prepare, it wasn't really usable
* resume_early, current resume, class resume.
- Updates power/state docs to be correct, and deprecate its usage except for
driver testing.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch is the first of this series that should actually change any
behavior ... by issuing the new event, now tha the rest of the kernel is
prepared to receive it.
This converts the PM core to issue the new PRETHAW message, which the rest of
the kernel is now ready to receive.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This teaches several USB host controller drivers to treat PRETHAW as a chip
reset since the controller, and all devices connected to it, are no longer in
states compatible with how the snapshotted suspend() left them.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Video drivers which explicitly test for messages reporting PM_EVENT_FREEZE
will now handle PM_EVENT_PRETHAW the same way.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Convert some framework code to handle the new PRETHAW message.
- IDE just treats it like a FREEZE.
- The pci_choose_state() thingie still doesn't use PCI_D0 when it gets a
FREEZE (and now PRETHAW) event, which seems rather buglike but wasn't
something to change with this patch.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This adds a new pm_message_t event type to use when preparing to restore a
swsusp snapshot. Devices that have been initialized by Linux after resume
(rather than left in power-up-reset state) may need to be reset; this new
event type give drivers the chance to do that.
The drivers that will care about this are those which understand more hardware
states than just "on" and "reset", relying on hardware state during resume()
methods to be either the state left by the preceding suspend(), or a
power-lost reset. The best current example of this class of drivers are USB
host controller drivers, which currently do not work through swsusp when
they're statically linked.
When the swsusp freeze/thaw mechanism kicks in, a troublesome third state
could exist: one state set up by a different kernel instance, before a
snapshot image is resumed. This mechanism lets drivers prevent that state.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Small driver suspend() fixes in preparation for the PRETHAW events:
- Only compare message events for equality against PM_EVENT_* codes;
not against integers, or using greater/less-than comparisons.
(PM_EVENT_* should really become a __bitwise thing.)
- Explicitly test for SUSPEND events (rather than not-something-else)
before suspending devices.
- Removes more of the confusion between a pm_message_t (wraps event code)
and a "state" ... suspend() originally took a target system state.
These updates are correct and appropriate even without new PM_EVENT codes.
benh: "I think in the Mesh case, we should handle the freeze case as well or
we might get wild DMA."
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Greg KH <greg@kroah.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix a goof in Linus' recent PM API updates: don't emit any messages in the
typical NOP "already suspended it" late suspend case.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Changes the PCI core to use the new suspend infrastructure changes.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Allow devices to participate in the suspend process more intimately,
in particular, allow the final phase (with interrupts disabled) to
also be open to normal devices, not just system devices.
Also, allow classes to participate in device suspend.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When no events have been reported by sysfs_notify(), sd->s_events
was previously set to zero. The initial value for new readers is
also zero, so poll was blocking, regardless of whether the attribute
was read by the process or not.
Make poll behave consistently by setting the initial value of
sd->s_events to non-zero.
Signed-off-by: Juha Yrjola <juha.yrjola@solidboot.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
deprecate PHYSDEV* values in the uevent environment
These values are no longer needed and inconsistent with the
stacking of class devices. The event environment should not
carry properties of a parent device. The key PHYSDEVDRIVER is
available as DRIVER, PHYDEVBUS is indentical SUBSYSTEM. Class
devices should not carry any of these values.
Signed-off-by: Kay Sievers <kay.sievers@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6:
[NetLabel]: update docs with website information
[NetLabel]: rework the Netlink attribute handling (part 2)
[NetLabel]: rework the Netlink attribute handling (part 1)
[Netlink]: add nla_validate_nested()
[NETLINK]: add nla_for_each_nested() to the interface list
[NetLabel]: change the SELinux permissions
[NetLabel]: make the CIPSOv4 cache spinlocks bottom half safe
[NetLabel]: correct improper handling of non-NetLabel peer contexts
[TCP]: make cubic the default
[TCP]: default congestion control menu
[ATM] he: Fix __init/__devinit conflict
[NETFILTER]: Add dscp,DSCP headers to header-y
[DCCP]: Introduce dccp_probe
[DCCP]: Use constants for CCIDs
[DCCP]: Introduce constants for CCID numbers
[DCCP]: Allow default/fallback service code.
* master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6:
[SOUND] sparc/amd7930: Use __devinit and __devinitdata as needed.
[SUNLANCE]: Mark sparc_lance_probe_one as __devinit.
[SPARC64]: Fix section-mismatch errors in solaris emul module.
The v4l2 API documentation for VIDIOC_ENUMSTD says:
To enumerate all standards applications shall begin at index
zero, incrementing by one until the driver returns EINVAL.
The actual code, however, tests the index this way:
if (index<=0 || index >= vfd->tvnormsize) {
ret=-EINVAL;
So any application which passes in index=0 gets EINVAL right off the bat
- and, in fact, this is what happens to mplayer. So I think the
following patch is called for, and maybe even appropriate for a 2.6.18.x
stable release.
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
