user/sven/linux.git/drivers/base/bus.c, branch v4.18.14

driver core: hold dev's parent lock when needed

2018-05-31T08:12:07Z

SoC have internal I/O buses that can't be proved for devices. The devices on the buses can be accessed directly without additinal configuration required. This type of bus is represented as "simple-bus". In some platforms, we name "soc" with "simple-bus" attribute and many devices are hooked under it described in DT (device tree). In commit bf74ad5bc417 ("Hold the device's parent's lock during probe and remove") to solve USB subsystem lock sequence since USB device's characteristic. Thus "soc" needs to be locked whenever a device and driver's probing happen under "soc" bus. During this period, an async driver tries to probe a device which is under the "soc" bus would be blocked until previous driver finish the probing and release "soc" lock. And the next probing under the "soc" bus need to wait for async finish. Because of that, driver's async probe for init time improvement will be shadowed. Since many devices don't have USB devices' characteristic, they actually don't need parent's lock. Thus, we introduce a lock flag in bus_type struct and driver core would lock the parent lock base on the flag. For USB, we set this flag in usb_bus_type to keep original lock behavior in driver core. Async probe could have more benefit after this patch. Signed-off-by: Martin Liu Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman

drivers: base: omit redundant interations

2017-12-18T15:47:27Z

When error happens, these interators return the error, no interation should be continued, so make the change for getting out of while immediately. Signed-off-by: Gimcuan Hui Signed-off-by: Greg Kroah-Hartman

driver core: Remove redundant license text

2017-12-07T17:36:44Z

Now that the SPDX tag is in all driver core files, that identifies the license in a specific and legally-defined manner. So the extra GPL text wording can be removed as it is no longer needed at all. This is done on a quest to remove the 700+ different ways that files in the kernel describe the GPL license text. And there's unneeded stuff like the address (sometimes incorrect) for the FSF which is never needed. No copyright headers or other non-license-description text was removed. Cc: Johannes Berg Cc: "Luis R. Rodriguez" Signed-off-by: Greg Kroah-Hartman

driver core: add SPDX identifiers to all driver core files

2017-12-07T17:36:43Z

It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the driver core files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Johannes Berg Cc: "Luis R. Rodriguez" Cc: William Breathitt Gray Cc: Thomas Gleixner Cc: Kate Stewart Cc: Philippe Ombredanne Signed-off-by: Greg Kroah-Hartman

driver core: bus: Fix a potential double free

2017-08-31T16:57:30Z

The .release function of driver_ktype is 'driver_release()'. This function frees the container_of this kobject. So, this memory must not be freed explicitly in the error handling path of 'bus_add_driver()'. Otherwise a double free will occur. Signed-off-by: Christophe JAILLET Cc: stable Signed-off-by: Greg Kroah-Hartman

driver-core: remove struct bus_type.dev_attrs

2017-06-12T14:18:37Z

Now that all in-kernel users of bus_type.dev_attrs have been converted to use dev_groups instead, the dev_attrs field, and logic surrounding it, can be removed. Signed-off-by: Greg Kroah-Hartman

kobject: support passing in variables for synthetic uevents

2017-05-25T16:30:51Z

This patch makes it possible to pass additional arguments in addition to uevent action name when writing /sys/.../uevent attribute. These additional arguments are then inserted into generated synthetic uevent as additional environment variables. Before, we were not able to pass any additional uevent environment variables for synthetic uevents. This made it hard to identify such uevents properly in userspace to make proper distinction between genuine uevents originating from kernel and synthetic uevents triggered from userspace. Also, it was not possible to pass any additional information which would make it possible to optimize and change the way the synthetic uevents are processed back in userspace based on the originating environment of the triggering action in userspace. With the extra additional variables, we are able to pass through this extra information needed and also it makes it possible to synchronize with such synthetic uevents as they can be clearly identified back in userspace. The format for writing the uevent attribute is following: ACTION [UUID [KEY=VALUE ...] There's no change in how "ACTION" is recognized - it stays the same ("add", "change", "remove"). The "ACTION" is the only argument required to generate synthetic uevent, the rest of arguments, that this patch adds support for, are optional. The "UUID" is considered as transaction identifier so it's possible to use the same UUID value for one or more synthetic uevents in which case we logically group these uevents together for any userspace listeners. The "UUID" is expected to be in "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" format where "x" is a hex digit. The value appears in uevent as "SYNTH_UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" environment variable. The "KEY=VALUE" pairs can contain alphanumeric characters only. It's possible to define zero or more more pairs - each pair is then delimited by a space character " ". Each pair appears in synthetic uevents as "SYNTH_ARG_KEY=VALUE" environment variable. That means the KEY name gains "SYNTH_ARG_" prefix to avoid possible collisions with existing variables. To pass the "KEY=VALUE" pairs, it's also required to pass in the "UUID" part for the synthetic uevent first. If "UUID" is not passed in, the generated synthetic uevent gains "SYNTH_UUID=0" environment variable automatically so it's possible to identify this situation in userspace when reading generated uevent and so we can still make a difference between genuine and synthetic uevents. Signed-off-by: Peter Rajnoha Signed-off-by: Greg Kroah-Hartman

driver core: bus: use to_subsys_private and to_device_private_bus

2016-02-10T01:25:27Z

Use to_subsys_private() and to_device_private_bus() instead of open-coding. Signed-off-by: Geliang Tang Signed-off-by: Greg Kroah-Hartman

driver core: bus: use list_for_each_entry*

2016-02-10T01:25:27Z

Use list_for_each_entry*() instead of list_for_each*() to simplify the code. Signed-off-by: Geliang Tang Signed-off-by: Greg Kroah-Hartman

driver-core: add asynchronous probing support for drivers

2015-05-20T07:25:24Z

Some devices take a long time when initializing, and not all drivers are suited to initialize their devices when they are open. For example, input drivers need to interrogate their devices in order to publish device's capabilities before userspace will open them. When such drivers are compiled into kernel they may stall entire kernel initialization. This change allows drivers request for their probe functions to be called asynchronously during driver and device registration (manual binding is still synchronous). Because async_schedule is used to perform asynchronous calls module loading will still wait for the probing to complete. Note that the end goal is to make the probing asynchronous by default, so annotating drivers with PROBE_PREFER_ASYNCHRONOUS is a temporary measure that allows us to speed up boot process while we validating and fixing the rest of the drivers and preparing userspace. This change is based on earlier patch by "Luis R. Rodriguez" Signed-off-by: Dmitry Torokhov Signed-off-by: Greg Kroah-Hartman