Commit graph

22 commits

Author SHA1 Message Date
Greg Kroah-Hartman
874c6241b2 [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.

Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-04 16:18:09 -08:00
Alan Stern
bf74ad5bc4 [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>
2006-01-04 16:18:08 -08:00
Alan Stern
2b08c8d046 [PATCH] Small fixes to driver core
This patch (as603) makes a few small fixes to the driver core:

Change spin_lock_irq for a klist lock to spin_lock;

Fix reference count leaks;

Minor spelling and formatting changes.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-23 23:03:06 -08:00
James Bottomley
34bb61f9dd [PATCH] fix klist semantics for lists which have elements removed on traversal
The problem is that klists claim to provide semantics for safe traversal of
lists which are being modified.  The failure case is when traversal of a
list causes element removal (a fairly common case).  The issue is that
although the list node is refcounted, if it is embedded in an object (which
is universally the case), then the object will be freed regardless of the
klist refcount leading to slab corruption because the klist iterator refers
to the prior element to get the next.

The solution is to make the klist take and release references to the
embedding object meaning that the embedding object won't be released until
the list relinquishes the reference to it.

(akpm: fast-track this because it's needed for the 2.6.13 scsi merge)

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-07 18:26:54 -07:00
James Bottomley
d856f1e337 [PATCH] klist: fix klist to have the same klist_add semantics as list_head
at the moment, the list_head semantics are

list_add(node, head)

whereas current klist semantics are

klist_add(head, node)

This is bound to cause confusion, and since klist is the newcomer, it
should follow the list_head semantics.

I also added missing include guards to klist.h

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-09-05 16:03:13 -07:00
Greg Kroah-Hartman
d65da6eae1 [PATCH] Fix manual binding infinite loop
Fix for manual binding of drivers to devices.  Problem is if you pass in
a valid device id, but the driver refuses to bind.  Infinite loop as
write() tries to resubmit the data it just sent.

Thanks to Michal Ostrowski <mostrows@watson.ibm.com> for pointing the
problem out.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-09-05 16:03:09 -07:00
Greg KH
518e654083 [PATCH] Fix manual binding infinite loop
Fix for manual binding of drivers to devices.  Problem is if you pass in
a valid device id, but the driver refuses to bind.  Infinite loop as
write() tries to resubmit the data it just sent.

Thanks to Michal Ostrowski <mostrows@watson.ibm.com> for pointing the
problem out.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-17 22:02:25 -07:00
Greg Kroah-Hartman
23d3d602cb [PATCH] driver core: change bus_rescan_devices to return void
No one was looking at the return value of bus_rescan_devices, and it
really wasn't anything that anyone in the kernel would ever care about.
So change it which enabled some counting code to be removed also.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-06-29 22:48:04 -07:00
Greg Kroah-Hartman
afdce75f1e [PATCH] driver core: Add the ability to bind drivers to devices from userspace
This adds a single file, "bind", to the sysfs directory of every driver
registered with the driver core.  To bind a device to a driver, write
the bus id of the device you wish to bind to that specific driver to the
"bind" file (remember to not add a trailing \n).  If that bus id matches
a device on that bus, and it does not currently have a driver bound to
it, the probe sequence will be initiated with that driver and device.

Note, this requires that the driver itself be willing and able to accept
that device (usually through a device id type table).  This patch does
not make it possible to override the driver's id table.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-06-29 22:48:04 -07:00
Greg Kroah-Hartman
151ef38f7c [PATCH] driver core: Add the ability to unbind drivers to devices from userspace
This adds a single file, "unbind", to the sysfs directory of every
device that is currently bound to a driver.  To unbind the driver from
the device, write anything to this file and they will be disconnected
from each other.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-06-29 22:48:04 -07:00
Cornelia Huck
0edb586049 [PATCH] driver core: add bus_find_device & driver_find_device functions
Add bus_find_device() and driver_find_device() which allow searching for a
device in the bus's resp. the driver's klist and obtain a reference on it.

Signed-off-by: Cornelia Huck <cohuck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-06-29 22:48:03 -07:00
Greg Kroah-Hartman
d377e85b53 [PATCH] driver core: Fix up the device_attach() error handling in bus_add_device()
Don't error out if something "bad" happens when trying to bind a driver to a
device.  We want the sysfs attributes to be present for later when we try to
tear down the device.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-06-22 23:01:10 -07:00
Hannes Reinecke
ca2b94ba12 [PATCH] driver core: fix error handling in bus_add_device
The error handling in bus_add_device() and device_attach() is simply
non-existing. This patch propagates any error from device_attach to
the upper layers to allow for a proper recovery.

From: Hannes Reinecke <hare@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-06-20 15:15:31 -07:00
mochel@digitalimplant.org
6eded061b1 [PATCH] Fix up bus code and remove use of rwsem.
- Don't add devices to bus's embedded kset, since it's not used by anyone anymore.
- Don't need to take the bus rwsem when calling {device,driver}_attach(), since
  those functions use the klists and the klists' spinlocks.

Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-06-20 15:15:18 -07:00
mochel@digitalimplant.org
38fdac3cdc [PATCH] Add a klist to struct bus_type for its drivers.
- Use it in bus_for_each_drv().
- Use the klist spinlock instead of the bus rwsem.

Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-06-20 15:15:14 -07:00
mochel@digitalimplant.org
465c7a3a3a [PATCH] Add a klist to struct bus_type for its devices.
- Use it for bus_for_each_dev().
- Use the klist spinlock instead of the bus rwsem.

Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-06-20 15:15:14 -07:00
mochel@digitalimplant.org
07e4a3e27f [PATCH] Move device/driver code to drivers/base/dd.c
This relocates the driver binding/unbinding code to drivers/base/dd.c. This is done
for two reasons: One, it's not code related to the bus_type itself; it uses some from
that, some from devices, and some from drivers. And Two, it will make it easier to do
some of the upcoming lock removal on that code..

Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-06-20 15:15:13 -07:00
mochel@digitalimplant.org
af70316af1 [PATCH] Add a semaphore to struct device to synchronize calls to its driver.
This adds a per-device semaphore that is taken before every call from the core to a
driver method. This prevents e.g. simultaneous calls to the ->suspend() or ->resume()
and ->probe() or ->release(), potentially saving a whole lot of headaches.

It also moves us a step closer to removing the bus rwsem, since it protects the fields
in struct device that are modified by the core.

Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-06-20 15:15:12 -07:00
Dmitry Torokhov
4a0c20bf8c [PATCH] sysfs: (driver/base) if show/store is missing return -EIO
sysfs: fix drivers/base so if an attribute doesn't implement
       show or store method read/write will return -EIO
       instead of 0.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-06-20 15:15:02 -07:00
David Brownell
0b405a0f7e [PATCH] Driver Core: remove driver model detach_state
The driver model has a "detach_state" mechanism that:

 - Has never been used by any in-kernel drive;
 - Is superfluous, since driver remove() methods can do the same thing;
 - Became buggy when the suspend() parameter changed semantics and type;
 - Could self-deadlock when called from certain suspend contexts;
 - Is effectively wasted documentation, object code, and headspace.

This removes that "detach_state" mechanism; net code shrink, as well
as a per-device saving in the driver model and sysfs.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-05-17 14:54:55 -07:00
Roman Kagan
b2d84f078a [PATCH] drivers/base/bus.c: fix iteration in driver_detach()
With 2.6.11 and 2.6.12-rc2 (and perhaps a few versions before) usb
drivers for multi-interface devices, which do
usb_driver_release_interface() in their disconnect(), make rmmod hang.

It turns out to be due to a bug in drivers/base/bus.c:driver_detach(),
that iterates over the list of attached devices with
list_for_each_safe() under an assumption that device_release_driver()
only releases the current device, while it may also call
device_release_driver() for other devices on the same list.

The following patch fixes it.  Please consider applying.

Signed-off-by: Roman Kagan <rkagan@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-05-04 23:44:38 -07:00
Linus Torvalds
1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00