kernel/git/stable/linux.git/drivers/base/dd.c, branch linux-4.17.y

driver core: Partially revert "driver core: correct device's shutdown order"

2018-07-28T05:57:17+00:00

commit 722e5f2b1eec7de61117b7c0a7914761e3da2eda upstream. Commit 52cdbdd49853 (driver core: correct device's shutdown order) introduced a regression by breaking device shutdown on some systems. Namely, the devices_kset_move_last() call in really_probe() added by that commit is a mistake as it may cause parents to follow children in the devices_kset list which then causes shutdown to fail. For example, if a device has children before really_probe() is called for it (which is not uncommon), that call will cause it to be reordered after the children in the devices_kset list and the ordering of that list will not reflect the correct device shutdown order any more. Also it causes the devices_kset list to be constantly reordered until all drivers have been probed which is totally pointless overhead in the majority of cases and it only covered an issue with system shutdown, while system-wide suspend/resume potentially had the same issue on the affected platforms (which was not covered). Moreover, the shutdown issue originally addressed by the change in really_probe() made by commit 52cdbdd49853 is not present in 4.18-rc any more, since dra7 started to use the sdhci-omap driver which doesn't disable any regulators during shutdown, so the really_probe() part of commit 52cdbdd49853 can be safely reverted. [The original issue was related to the omap_hsmmc driver used by dra7 previously.] For the above reasons, revert the really_probe() modifications made by commit 52cdbdd49853. The other code changes made by commit 52cdbdd49853 are useful and they need not be reverted. Fixes: 52cdbdd49853 (driver core: correct device's shutdown order) Link: https://lore.kernel.org/lkml/CAFgQCTt7VfqM=UyCnvNFxrSw8Z6cUtAi3HUwR4_xPAc03SgHjQ@mail.gmail.com/ Reported-by: Pingfan Liu Tested-by: Pingfan Liu Reviewed-by: Kishon Vijay Abraham I Signed-off-by: Rafael J. Wysocki Cc: stable Signed-off-by: Greg Kroah-Hartman

drivers: base: remove check for callback in coredump_store()

2018-03-23T17:08:02+00:00

The check for the .coredump() callback in coredump_store() is redundant. It is already assured the device driver implements the callback upon creating the coredump sysfs entry. Signed-off-by: Arend van Spriel Signed-off-by: Greg Kroah-Hartman

drivers: base: add coredump driver ops

2018-01-23T08:47:05+00:00

This adds the coredump driver operation. When the driver defines it a coredump file is added in the sysfs folder of the device upon driver binding. The file is removed when the driver is unbound. User-space can trigger a coredump for this device by echo'ing to the coredump file. Signed-off-by: Arend van Spriel Signed-off-by: Greg Kroah-Hartman

driver core: Remove redundant license text

2017-12-07T17:36:44+00:00

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

2017-12-07T17:36:43+00:00

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

Merge tag 'driver-core-4.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2017-11-16T16:55:30+00:00

Pull driver core updates from Greg KH: "Here is the set of driver core / debugfs patches for 4.15-rc1. Not many here, mostly all are debugfs fixes to resolve some long-reported problems with files going away with references to them in userspace. There's also some SPDX cleanups for the debugfs code, as well as a few other minor driver core changes for issues reported by people. All of these have been in linux-next for a week or more with no reported issues" * tag 'driver-core-4.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: driver core: Fix device link deferred probe debugfs: Remove redundant license text debugfs: add SPDX identifiers to all debugfs files debugfs: defer debugfs_fsdata allocation to first usage debugfs: call debugfs_real_fops() only after debugfs_file_get() debugfs: purge obsolete SRCU based removal protection IB/hfi1: convert to debugfs_file_get() and -put() debugfs: convert to debugfs_file_get() and -put() debugfs: debugfs_real_fops(): drop __must_hold sparse annotation debugfs: implement per-file removal protection debugfs: add support for more elaborate ->d_fsdata driver core: Move device_links_purge() after bus_remove_device() arch_topology: Fix section miss match warning due to free_raw_capacity() driver-core: pr_err() strings should end with newlines

driver core: Fix device link deferred probe

2017-11-08T12:50:17+00:00

A device probe deferred because of a device link is never probed again because it is not added to the deferred_probe_pending_list. Add it, taking care of the race with driver_deferred_probe_trigger(). Signed-off-by: Adrian Hunter Reviewed-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

PM / core: Add NEVER_SKIP and SMART_PREPARE driver flags

2017-11-06T12:55:30+00:00

The motivation for this change is to provide a way to work around a problem with the direct-complete mechanism used for avoiding system suspend/resume handling for devices in runtime suspend. The problem is that some middle layer code (the PCI bus type and the ACPI PM domain in particular) returns positive values from its system suspend ->prepare callbacks regardless of whether the driver's ->prepare returns a positive value or 0, which effectively prevents drivers from being able to control the direct-complete feature. Some drivers need that control, however, and the PCI bus type has grown its own flag to deal with this issue, but since it is not limited to PCI, it is better to address it by adding driver flags at the core level. To that end, add a driver_flags field to struct dev_pm_info for flags that can be set by device drivers at the probe time to inform the PM core and/or bus types, PM domains and so on on the capabilities and/or preferences of device drivers. Also add two static inline helpers for setting that field and testing it against a given set of flags and make the driver core clear it automatically on driver remove and probe failures. Define and document two PM driver flags related to the direct- complete feature: NEVER_SKIP and SMART_PREPARE that can be used, respectively, to indicate to the PM core that the direct-complete mechanism should never be used for the device and to inform the middle layer code (bus types, PM domains etc) that it can only request the PM core to use the direct-complete mechanism for the device (by returning a positive value from its ->prepare callback) if it also has been requested by the driver. While at it, make the core check pm_runtime_suspended() when setting power.direct_complete so that it doesn't need to be checked by ->prepare callbacks. Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman Acked-by: Bjorn Helgaas Reviewed-by: Ulf Hansson

initcall_debug: add deferred probe times

2017-08-04T00:48:49+00:00

initcall_debug attributes all deferred device probe retries for the late_initcall level to function deferred_probe_initcall. Add logs of the individual device probe routines called, to identify which drivers are executing for how long during the initcall path. Deferred probes that occur after initcall processing are not shown. Example log messages added: [ 0.505119] deferred probe my-sound-device @ 6 [ 0.517656] deferred probe my-sound-device returned after 1227 usecs Signed-off-by: Todd Poynor Signed-off-by: Greg Kroah-Hartman

driver core: emit uevents when device is bound to a driver

2017-07-22T09:59:23+00:00

There are certain touch controllers that may come up in either normal (application) or boot mode, depending on whether firmware/configuration is corrupted when they are powered on. In boot mode the kernel does not create input device instance (because it does not necessarily know the characteristics of the input device in question). Another number of controllers does not store firmware in a non-volatile memory, and they similarly need to have firmware loaded before input device instance is created. There are also other types of devices with similar behavior. There is a desire to be able to trigger firmware loading via udev, but it has to happen only when driver is bound to a physical device (i2c or spi). These udev actions can not use ADD events, as those happen too early, so we are introducing BIND and UNBIND events that are emitted at the right moment. Also, many drivers create additional driver-specific device attributes when binding to the device, to provide userspace with additional controls. The new events allow userspace to adjust these driver-specific attributes without worrying that they are not there yet. Signed-off-by: Dmitry Torokhov Signed-off-by: Greg Kroah-Hartman