Commit Graph

77 Commits

Author SHA1 Message Date
Greg Kroah-Hartman
99178b036c Driver core: add bus_sort_breadthfirst() function
The PCI core wants to reorder the devices in the bus list.  So move this
functionality out of the pci core and into the driver core so that
anyone else can also do this if needed.  This also lets us change how
struct device is attached to drivers in the future without messing with
the PCI core.

Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-10-16 09:24:52 -07:00
Peter Korsgaard
3ce24d8d93 Driver core: make bus_find_device_by_name() more robust
Use sysfs_streq() in bus_find_device_by_name() so trailing newlines
are ignored (E.G. in bind/unbind).

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-10-16 09:24:51 -07:00
Rafael J. Wysocki
29591b92e1 bus_remove_device: be more careful about incomplete initialization
Prevent bus_remove_device() from crashing if dev->knode_bus has not been
initialized before it's called.

This can happen if the device_add() ended up breaking out early due to
an error, for example.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-22 17:40:36 -07:00
Harvey Harrison
2b3a302a09 driver core: replace remaining __FUNCTION__ occurrences
__FUNCTION__ is gcc-specific, use __func__

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-04-19 19:10:29 -07:00
Greg Kroah-Hartman
3f62e5700b Driver core: make device_is_registered() work for class devices
device_is_registered() can use the kobject value for this, so it will
now work with devices that are associated with only a class, not a bus
and a driver.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-04-19 19:10:26 -07:00
Cornelia Huck
0763446429 Driver core: Fix error handling in bus_add_driver().
- If the allocation of ->priv fails, the reference on the bus
  must be dropped.
- If adding the kobject fails, kobject_put must be called to
  clean things up.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-21 15:27:07 -08:00
Greg Kroah-Hartman
1f9ffc049d Driver core: add bus_find_device_by_name function
The driver core, and some other parts of the kernel just want to find a
device based on a name for a specific bus.  Give them a simple wrapper
to prevent them from having to always roll their own.

This will be used in the PPC patch later in this series.

Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-27 15:01:39 -08:00
Greg Kroah-Hartman
4a3ad20ccd Driver core: coding style fixes
Fix up a number of coding style issues in the drivers/base/ directory
that have annoyed me over the years.  checkpatch.pl is now very happy.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 22:50:12 -08:00
Greg Kroah-Hartman
c10997f657 Kobject: convert drivers/* from kobject_unregister() to kobject_put()
There is no need for kobject_unregister() anymore, thanks to Kay's
kobject cleanup changes, so replace all instances of it with
kobject_put().


Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:40 -08:00
Greg Kroah-Hartman
c8e90d822b Kobject: change drivers/base/bus to use kobject_init_and_add
Stop using kobject_register, as this way we can control the sending of
the uevent properly, after everything is properly initialized.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:35 -08:00
Greg Kroah-Hartman
7dc72b2842 Driver core: clean up debugging messages
The driver core debugging messages are a mess.  This provides a unified
message that makes them actually useful.

The format for new kobject debug messages should be:
	driver/bus/class: 'OBJECT_NAME': FUNCTION_NAME: message.\n

Note, the class code is not changed in this patch due to pending patches
in my queue that this would conflict with.  A later patch will clean
them up.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:35 -08:00
Greg Kroah-Hartman
e5dd127846 Driver core: move the static kobject out of struct driver
This patch removes the kobject, and a few other driver-core-only fields
out of struct driver and into the driver core only.  Now drivers can be
safely create on the stack or statically (like they currently are.)

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:35 -08:00
Greg Kroah-Hartman
c6f7e72a3f driver core: remove fields from struct bus_type
struct bus_type is static everywhere in the kernel.  This moves the
kobject in the structure out of it, and a bunch of other private only to
the driver core fields are now moved to a private structure.  This lets
us dynamically create the backing kobject properly and gives us the
chance to be able to document to users exactly how to use the struct
bus_type as there are no fields they can improperly access.

Thanks to Kay for the build fixes on this patch.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:33 -08:00
Greg Kroah-Hartman
b249072ee6 driver core: add way to get to bus device klist
This allows an easier way to get to the device klist associated with a
struct bus_type (you have three to choose from...)  This will make it
easier to move these fields to be dynamic in a future patch.

The only user of this is the PCI core which horribly abuses this
interface to rearrange the order of the pci devices.  This should be
done using the existing bus device walking functions, but that's left
for future patches.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:33 -08:00
Greg Kroah-Hartman
0fed80f7a6 driver core: add way to get to bus kset
This allows an easier way to get to the kset associated with a struct
bus_type (you have three to choose from...)  This will make it easier to
move these fields to be dynamic in a future patch.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:33 -08:00
Greg Kroah-Hartman
2fb9113b97 kobject: remove subsystem_(un)register functions
These functions are no longer used and are the last remants of the old
subsystem crap.  So delete them for good.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:24 -08:00
Greg Kroah-Hartman
6dcec2511f kset: convert struct bus_device->drivers to use kset_create
Dynamically create the kset instead of declaring it statically.

Having 3 static kobjects in one structure is not only foolish, but ripe
for nasty race conditions if handled improperly.  We also rename the
field to catch any potential users of it (not that there should be
outside of the driver core...)

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:16 -08:00
Greg Kroah-Hartman
3d8995963d kset: convert struct bus_device->devices to use kset_create
Dynamically create the kset instead of declaring it statically.

Having 3 static kobjects in one structure is not only foolish, but ripe
for nasty race conditions if handled improperly.  We also rename the
field to catch any potential users of it (not that there should be
outside of the driver core...)

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:16 -08:00
Greg Kroah-Hartman
59a548338a kset: convert drivers/base/bus.c to use kset_create
Dynamically create the kset instead of declaring it statically.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:14 -08:00
Greg Kroah-Hartman
3514faca19 kobject: remove struct kobj_type from struct kset
We don't need a "default" ktype for a kset.  We should set this
explicitly every time for each kset.  This change is needed so that we
can make ksets dynamic, and cleans up one of the odd, undocumented
assumption that the kset/kobject/ktype model has.

This patch is based on a lot of help from Kay Sievers.

Nasty bug in the block code was found by Dave Young
<hidave.darkstar@gmail.com>

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24 20:40:10 -08:00
Greg Kroah-Hartman
a1148fb03f Driver core: rename ktype_driver
This makes it a bit more sane when trying to figure out how to clean up
the ktype mess.

Based on a larger patch from Kay Sievers

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12 14:51:12 -07:00
Kay Sievers
7ac1cf4a87 Driver core: add uevent file for bus and driver
This has been in the SuSE kernels for some time now.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12 14:51:06 -07:00
Greg Kroah-Hartman
5901d0145c Driver core: remove get_bus()
get_bus() should not be globally visable as it is not used by anything
other than drivers/base/bus.c.  This patch removes the visability of it,
and renames it to match all of the other *_get() functions in the
kernel.


Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12 14:51:02 -07:00
Greg Kroah-Hartman
fc1ede5888 Driver core: remove put_bus()
put_bus() should not be globally visable as it is not used by anything
other than drivers/base/bus.c.  This patch removes the visability of it,
and renames it to match all of the other *_put() functions in the
kernel.


Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12 14:51:02 -07:00
Greg Kroah-Hartman
1ef4cfac01 Driver core: remove subsys_get()
There are no more subsystems, it's a kset now so remove the function and
the only two users, which are in the driver core.


Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12 14:51:01 -07:00
Greg Kroah-Hartman
6e9d930d16 Driver core: remove subsys_put()
There are no more subsystems, it's a kset now so remove the function and
the only two users, which are in the driver core.


Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12 14:51:01 -07:00
Greg Kroah-Hartman
d6b05b84ed Driver core: remove subsys_set_kset
This macro is only used by the driver core and is held over from when we
had subsystems.  It is not needed anymore.


Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12 14:51:01 -07:00
Kay Sievers
8380770c84 Driver core: make sysfs uevent-attributes static
Attributes do not have an owner(module) anymore, so there is no need
to carry the attributes in every single bus instance.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Acked-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12 14:50:59 -07:00
Tejun Heo
7b595756ec sysfs: kill unnecessary attribute->owner
sysfs is now completely out of driver/module lifetime game.  After
deletion, a sysfs node doesn't access anything outside sysfs proper,
so there's no reason to hold onto the attribute owners.  Note that
often the wrong modules were accounted for as owners leading to
accessing removed modules.

This patch kills now unnecessary attribute->owner.  Note that with
this change, userland holding a sysfs node does not prevent the
backing module from being unloaded.

For more info regarding lifetime rule cleanup, please read the
following message.

  http://article.gmane.org/gmane.linux.kernel/510293

(tweaked by Greg to not delete the field just yet, to make it easier to
merge things properly.)

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-07-11 16:09:06 -07:00
Cornelia Huck
dc0afa8388 Driver core: coding style cleanup
This converts code of the form

	if ((error = some_func()))
		goto fixup;
to
	error = some_func();
	if (error)
		goto fixup;

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-07-11 16:09:02 -07:00
Kay Sievers
80f03e349f Driver core: add missing kset uevent
We get uevents for a bus/class going away, but not one registering.
Add the missing uevent in kset_register(), which will send an
event for a new bus/class. Suppress all unwanted uevents for bus
subdirectories like /bus/*/devices/, /bus/*/drivers/.

Now we get for module usbcore:
  add      /module/usbcore (module)
  add      /bus/usb (bus)
  add      /class/usb_host (class)
  add      /bus/usb/drivers/hub (drivers)
  add      /bus/usb/drivers/usb (drivers)
  remove   /bus/usb/drivers/usb (drivers)
  remove   /bus/usb/drivers/hub (drivers)
  remove   /class/usb_host (class)
  remove   /bus/usb (bus)
  remove   /module/usbcore (module)

instead of:
  add      /module/usbcore (module)
  add      /bus/usb/drivers/hub (drivers)
  add      /bus/usb/drivers/usb (drivers)
  remove   /bus/usb/drivers/usb (drivers)
  remove   /bus/usb/drivers/hub (drivers)
  remove   /class/usb_host (class)
  remove   /bus/usb/drivers (bus)
  remove   /bus/usb/devices (bus)
  remove   /bus/usb (bus)
  remove   /module/usbcore (module)

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-07-11 16:09:01 -07:00
Greg Kroah-Hartman
823bccfc40 remove "struct subsystem" as it is no longer needed
We need to work on cleaning up the relationship between kobjects, ksets and
ktypes.  The removal of 'struct subsystem' is the first step of this,
especially as it is not really needed at all.

Thanks to Kay for fixing the bugs in this patch.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-05-02 18:57:59 -07:00
Greg Kroah-Hartman
4f6e1945fe driver core: bus_add_driver should return an error if no bus
As pointed out by Dave Jones.

Cc: Dave Jones <davej@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-04-27 10:57:32 -07:00
Greg Kroah-Hartman
74e9f5fa15 Driver core: remove unneeded completion from driver release path
The completion in the driver release path is due to ancient history in
the _very_ early 2.5 days when we were not tracking the module reference
count of attributes.  It is not needed at all and can be removed.

Note, we now have an empty release function for the driver structure.
This is due to the fact that drivers are statically allocated in the
system at this point in time, something which I want to change in the
future.  But remember, drivers are really code, which is reference
counted by the module, unlike devices, which are data and _must_ be
reference counted properly in order to work correctly.


Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-04-27 10:57:29 -07:00
Cornelia Huck
c6a46696f9 driver core: don't fail attaching the device if it cannot be bound
Don't fail bus_attach_device() if the device cannot be bound.

If dev->driver has been specified, reset it to NULL if device_bind_driver()
failed and add the device as an unbound device.  As a result,
bus_attach_device() now cannot fail, and we can remove some checking from
device_add().

Also remove an unneeded check in bus_rescan_devices_helper().

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-04-27 10:57:29 -07:00
Kay Sievers
b8c5cec23d Driver core: udev triggered device-<>driver binding
We get two per-bus sysfs files:
  ls-l /sys/subsystem/usb
  drwxr-xr-x 2 root root    0 2007-02-16 16:42 devices
  drwxr-xr-x 7 root root    0 2007-02-16 14:55 drivers
  -rw-r--r-- 1 root root 4096 2007-02-16 16:42 drivers_autoprobe
  --w------- 1 root root 4096 2007-02-16 16:42 drivers_probe

The flag "drivers_autoprobe" controls the behavior of the bus to bind
devices by default, or just initialize the device and leave it alone.

The command "drivers_probe" accepts a bus_id and the bus tries to bind a
driver to this device.

Systems who want to control the driver binding with udev, switch off the
bus initiated probing:
  echo 0 > /sys/subsystem/usb/drivers_autoprobe
  echo 0 > /sys/subsystem/pcmcia/drivers_autoprobe
  ...

and initiate the probing with udev rules like:
  ACTION=="add", SUBSYSTEM=="usb", ATTR{subsystem/drivers_probe}="$kernel"
  ACTION=="add", SUBSYSTEM=="pcmcia", ATTR{subsystem/drivers_probe}="$kernel"
  ...

Custom driver binding can happen in earlier rules by something like:
  ACTION=="add", SUBSYSTEM=="usb", \
  ATTRS{idVendor}=="1234", ATTRS{idProduct}=="5678" \
  ATTR{subsystem/drivers/<custom-driver>/bind}="$kernel"

This is intended to solve the modprobe.conf mess with "install-rules", custom
bind/unbind-scripts and all the weird things people invented over the years.
It should also provide the functionality "libusual" was supposed to do.

With udev, one can just write a udev rule to drive all USB-disks at the
third port of USB-hub by the "ub" driver, and everything else by
usb-storage. One can also instruct udev to bind different wireless
drivers to identical cards - just selected by the pcmcia slot-number, and
whatever ...

To use the mentioned rules, it needs udev version 106, to be able to
write ATTR{}="$kernel" to sysfs files.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-04-27 10:57:28 -07:00
Andrew Morton
4aca67e5f5 Driver core: device_add_attrs() cleanup
Clean up the coding in device_add_attrs() a bit.

Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-16 15:19:18 -08:00
Kay Sievers
b9cafc7d5b CONFIG_SYSFS_DEPRECATED - bus symlinks
Turn off the bus symlinks if CONFIG_SYSFS_DEPRECATED is enabled

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-12-01 14:51:58 -08:00
Benjamin Herrenschmidt
116af37820 Driver core: add notification of bus events
I finally did as you suggested and added the notifier to the struct
bus_type itself. There are still problems to be expected is something
attaches to a bus type where the code can hook in different struct
device sub-classes (which is imho a big bogosity but I won't even try to
argue that case now) but it will solve nicely a number of issues I've
had so far.

That also means that clients interested in registering for such
notifications have to do it before devices are added and after bus types
are registered. Fortunately, most bus types that matter for the various
usage scenarios I have in mind are registerd at postcore_initcall time,
which means I have a really nice spot at arch_initcall time to add my
notifiers.

There are 4 notifications provided. Device being added (before hooked to
the bus) and removed (failure of previous case or after being unhooked
from the bus), along with driver being bound to a device and about to be
unbound.

The usage I have for these are:

 - The 2 first ones are used to maintain a struct device_ext that is
hooked to struct device.firmware_data. This structure contains for now a
pointer to the Open Firmware node related to the device (if any), the
NUMA node ID (for quick access to it) and the DMA operations pointers &
iommu table instance for DMA to/from this device. For bus types I own
(like IBM VIO or EBUS), I just maintain that structure directly from the
bus code when creating the devices. But for bus types managed by generic
code like PCI or platform (actually, of_platform which is a variation of
platform linked to Open Firmware device-tree), I need this notifier.

 - The other two ones have a completely different usage scenario. I have
cases where multiple devices and their drivers depend on each other. For
example, the IBM EMAC network driver needs to attach to a MAL DMA engine
which is a separate device, and a PHY interface which is also a separate
device. They are all of_platform_device's (well, about to be with my
upcoming patches) but there is no say in what precise order the core
will "probe" them and instanciate the various modules. The solution I
found for that is to have the drivers for emac to use multithread_probe,
and wait for a driver to be bound to the target MAL and PHY control
devices (the device-tree contains reference to the MAL and PHY interface
nodes, which I can then match to of_platform_devices). Right now, I've
been polling, but with that notifier, I can more cleanly wait (with a
timeout of course).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-12-01 14:51:58 -08:00
Jeff Garzik
d9fd4d3b31 Driver core: bus: remove indentation level
Before potentially fixing up these functions, this cosmetic change
reduces the indentation level to make the code easier to read and
maintain.

No functional changes at all.

Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-10-18 12:49:56 -07:00
Alan Stern
f70fa6296c Driver core: Don't ignore error returns from probing
This patch (as797) fixes device_add() in the driver core.  It needs to
pay attention when the driver for a new device reports an error.

At the same time, since bus_remove_device() undoes the effects of both
bus_add_device() and bus_attach_device(), it needs to check whether
the bus_attach_device step failed.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-10-18 12:49:55 -07:00
Cornelia Huck
513e7337ad driver core fixes: bus_add_device() cleanup on error
Correct cleanup in the error path of bus_add_device().

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-10-18 12:49:55 -07:00
Cornelia Huck
1bb6881aca driver core fixes: bus_add_attrs() retval check
Check return value of bus_add_attrs() in bus_register().

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-10-18 12:49:55 -07:00
Alan Stern
81107bf531 Driver core: Remove unneeded routines from driver core
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>
2006-09-25 21:08:40 -07:00
Alan Stern
f2eaae197f Driver core: Fix potential deadlock in driver core
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>
2006-09-25 21:08:40 -07:00
Andrew Morton
f86db396ff drivers/base: check errors
Add lots of return-value checking.

<pcornelia.huck@de.ibm.com>: fix bus_rescan_devices()]
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-25 21:08:39 -07:00
Yoichi Yuasa
35acfdd725 Driver core: fixed add_bind_files() definition
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>
2006-09-25 21:08:39 -07:00
Adrian Bunk
7e4ef085ea [PATCH] Driver core: bus.c cleanups
This patch contains the following cleanups:
- make the needlessly global bus_subsys static
- #if 0 the unused find_bus()

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-07-12 16:09:08 -07:00
Jörn Engel
6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00
Kay Sievers
b9d9c82b4d [PATCH] Driver core: add generic "subsystem" link to all devices
Like the SUBSYTEM= key we find in the environment of the uevent, this
creates a generic "subsystem" link in sysfs for every device. Userspace
usually doesn't care at all if its a "class" or a "bus" device. This
provides an unified way to determine the subsytem of a device, regardless
of the way the driver core has created it.

Signed-off-by: Kay Sievers <kay.sievers@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-06-21 12:40:49 -07:00