linux-stable.git/include/linux/device.h, branch linux-2.6.19.y

[PATCH] Remove __must_check for device_for_each_child()

2006-10-23T18:01:33+00:00

Eliminate more __must_check madness.

The return code from device_for_each_child() depends on the values
which the helper function returns.  If the helper function always
returns zero, it's utterly pointless to check the return code from
device_for_each_child().

The only code which knows if the return value should be checked is
the caller itself, so forcing the return code to always be checked
is silly.  Hence, remove the __must_check annotation.

Signed-off-by: Russell King 
Signed-off-by: Linus Torvalds

Driver core: Fix potential deadlock in driver core

2006-09-26T04:08:40+00:00

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 
Signed-off-by: Greg Kroah-Hartman

Driver Core: add ability for drivers to do a threaded probe

2006-09-26T04:08:40+00:00

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

drivers/base: check errors

2006-09-26T04:08:39+00:00

Add lots of return-value checking.

: fix bus_rescan_devices()]
Cc: "Randy.Dunlap" 
Signed-off-by: Cornelia Huck 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

add __must_check to device management code

2006-09-26T04:08:39+00:00

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 
Signed-off-by: Greg Kroah-Hartman

Driver core: add ability for devices to create and remove bin files

2006-09-26T04:08:39+00:00

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

Class: add support for class interfaces for devices

2006-09-26T04:08:38+00:00

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

Driver core: create devices/virtual/ tree

2006-09-26T04:08:38+00:00

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 
Signed-off-by: Greg Kroah-Hartman

Driver core: add device_rename function

2006-09-26T04:08:38+00:00

The network layer needs this to convert to using struct device instead
of a struct class_device.

Signed-off-by: Greg Kroah-Hartman

Driver core: add ability for classes to handle devices properly

2006-09-26T04:08:38+00:00

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