linux/drivers/base/base.h, branch v4.1

driver core: Move driver_data back to struct device

2014-05-27T19:37:18Z

Having to allocate memory as part of dev_set_drvdata() is a problem because that memory may never get freed if the device itself is not created. So move driver_data back to struct device. This is a partial revert of commit b4028437. Signed-off-by: Jean Delvare Signed-off-by: Greg Kroah-Hartman

ACPI / hotplug / driver core: Handle containers in a special way

2013-12-29T14:25:48Z

ACPI container devices require special hotplug handling, at least on some systems, since generally user space needs to carry out system-specific cleanup before it makes sense to offline devices in the container. However, the current ACPI hotplug code for containers first attempts to offline devices in the container and only then it notifies user space of the container offline. Moreover, after commit 202317a573b2 (ACPI / scan: Add acpi_device objects for all device nodes in the namespace), ACPI device objects representing containers are present as long as the ACPI namespace nodes corresponding to them are present, which may be forever, even if the container devices are physically detached from the system (the return values of the corresponding _STA methods change in those cases, but generally the namespace nodes themselves are still there). Thus it is useful to introduce entities representing containers that will go away during container hot-unplug. The goal of this change is to address both the above issues. The idea is to create a "companion" container system device for each of the ACPI container device objects during the initial namespace scan or on a hotplug event making the container present. That system device will be unregistered on container removal. A new bus type for container devices is added for this purpose, because device offline and online operations need to be defined for them. The online operation is a trivial function that is always successful and the offline uses a callback pointed to by the container device's offline member. For ACPI containers that callback simply walks the list of ACPI device objects right below the container object (its children) and checks if all of their physical companion devices are offline. If that's not the case, it returns -EBUSY and the container system devivce cannot be put offline. Consequently, to put the container system device offline, it is necessary to put all of the physical devices depending on its ACPI companion object offline beforehand. Container system devices created for ACPI container objects are initially online. They are created by the container ACPI scan handler whose hotplug.demand_offline flag is set. That causes acpi_scan_hot_remove() to check if the companion container system device is offline before attempting to remove an ACPI container or any devices below it. If the check fails, a KOBJ_CHANGE uevent is emitted for the container system device in question and user space is expected to offline all devices below the container and the container itself in response to it. Then, user space can finalize the removal of the container with the help of its ACPI device object's eject attribute in sysfs. Tested-by: Yasuaki Ishimatsu Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman

driver core: bus_type: add drv_groups

2013-08-12T22:33:31Z

attribute groups are much more flexible than just a list of attributes, due to their support for visibility of the attributes, and binary attributes. Add drv_groups to struct bus_type which should be used instead of drv_attrs. drv_attrs will be removed from the structure soon. Signed-off-by: Greg Kroah-Hartman

driver core: bus_type: add dev_groups

2013-08-12T22:33:31Z

attribute groups are much more flexible than just a list of attributes, due to their support for visibility of the attributes, and binary attributes. Add dev_groups to struct bus_type which should be used instead of dev_attrs. dev_attrs will be removed from the structure soon. Signed-off-by: Greg Kroah-Hartman

driver/base: implement subsys_virtual_register()

2013-03-12T18:36:35Z

Kay tells me the most appropriate place to expose workqueues to userland would be /sys/devices/virtual/workqueues/WQ_NAME which is symlinked to /sys/bus/workqueue/devices/WQ_NAME and that we're lacking a way to do that outside of driver core as virtual_device_parent() isn't exported and there's no inteface to conveniently create a virtual subsystem. This patch implements subsys_virtual_register() by factoring out subsys_register() from subsys_system_register() and using it with virtual_device_parent() as the origin directory. It's identical to subsys_system_register() other than the origin directory but we aren't gonna restrict the device names which should be used under it. This will be used to expose workqueue attributes to userland. Signed-off-by: Tejun Heo Acked-by: Greg Kroah-Hartman Cc: Kay Sievers

driver core: move the deferred probe pointer into the private area

2012-03-08T20:17:22Z

Nothing outside of the driver core needs to get to the deferred probe pointer, so move it inside the private area of 'struct device' so no one tries to mess around with it. Cc: Grant Likely Signed-off-by: Greg Kroah-Hartman

drivercore: Add driver probe deferral mechanism

2012-03-08T19:53:13Z

Allow drivers to report at probe time that they cannot get all the resources required by the device, and should be retried at a later time. This should completely solve the problem of getting devices initialized in the right order. Right now this is mostly handled by mucking about with initcall ordering which is a complete hack, and doesn't even remotely handle the case where device drivers are in modules. This approach completely sidesteps the issues by allowing driver registration to occur in any order, and any driver can request to be retried after a few more other drivers get probed. v4: - Integrate Manjunath's addition of a separate workqueue - Change -EAGAIN to -EPROBE_DEFER for drivers to trigger deferral - Update comment blocks to reflect how the code really works v3: - Hold off workqueue scheduling until late_initcall so that the bulk of driver probes are complete before we start retrying deferred devices. - Tested with simple use cases. Still needs more testing though. Using it to get rid of the gpio early_initcall madness, or to replace the ASoC internal probe deferral code would be ideal. v2: - added locking so it should no longer be utterly broken in that regard - remove device from deferred list at device_del time. - Still completely untested with any real use case, but has been boot tested. Signed-off-by: Grant Likely Cc: Mark Brown Cc: Arnd Bergmann Cc: Dilan Lee Cc: Manjunath GKondaiah Cc: Alan Stern Cc: Tony Lindgren Cc: Alan Cox Reviewed-by: Mark Brown Acked-by: David Daney Reviewed-by: Arnd Bergmann Signed-off-by: Greg Kroah-Hartman

cpu: Do not return errors from cpu_dev_init() which will be ignored

2012-01-11T23:49:43Z

cpu_dev_init() is only called from driver_init(), which does not check its return value. Therefore make cpu_dev_init() return void. We must register the CPU subsystem, so panic if this fails. If sched_create_sysfs_power_savings_entries() fails, the damage is contained, so ignore this (as before). Signed-off-by: Ben Hutchings Signed-off-by: Linus Torvalds

driver-core: implement 'sysdev' functionality for regular devices and buses

2011-12-14T22:29:38Z

All sysdev classes and sysdev devices will converted to regular devices and buses to properly hook userspace into the event processing. There is no interesting difference between a 'sysdev' and 'device' which would justify to roll an entire own subsystem with different userspace export semantics. Userspace relies on events and generic sysfs subsystem infrastructure from sysdev devices, which are currently not properly available. Every converted sysdev class will create a regular device with the class name in /sys/devices/system and all registered devices will becom a children of theses devices. For compatibility reasons, the sysdev class-wide attributes are created at this parent device. (Do not copy that logic for anything new, subsystem- wide properties belong to the subsystem, not to some fake parent device created in /sys/devices.) Every sysdev driver is implemented as a simple subsystem interface now, and no longer called a driver. After all sysdev classes are ported to regular driver core entities, the sysdev implementation will be entirely removed from the kernel. Signed-off-by: Kay Sievers Signed-off-by: Greg Kroah-Hartman

drivers/base: base.h implicitly depends on

2011-10-31T23:31:39Z

This file is currently relying on sneaking it in through the implicit include paths from device.h. Once that is cleaned up, this will happen: In file included from drivers/base/init.c:12: drivers/base/base.h:34: error: field ‘bus_notifier’ has incomplete type make[3]: *** [drivers/base/init.o] Error 1 Fix it up in advance, so the cleanup can continue. Signed-off-by: Paul Gortmaker