[PATCH v2 0/4] driver core: generalize driver_override infrastructure

[Danilo Krummrich <dakr@kernel.org>]

Currently, there are 12 busses (including platform and PCI) that duplicate the
driver_override logic for their individual devices.

All of them seem to be prone to the bug described in [1].

While this could be solved for every bus individually using a separate lock,
solving this in the driver-core generically results in less (and cleaner)
changes overall.

Thus, move driver_override to struct device, provide corresponding accessors for
busses and handle locking with a separate lock internally.

In particular, add device_set_driver_override(), device_has_driver_override(),
device_match_driver_override() and a helper, DEVICE_ATTR_DRIVER_OVERRIDE(), to
declare the corresponding sysfs store() and show() callbacks.

Until all busses have migrated, keep driver_set_override() in place.

Note that we can't use the device lock for the reasons described in [2].

This patch series includes the migration of the platform bus; patches for all
other affected busses still need to be extracted as a follow-up of the WIP
treewide patch in [3].

[1] https://bugzilla.kernel.org/show_bug.cgi?id=220789
[2] https://lore.kernel.org/driver-core/DGRGTIRHA62X.3RY09D9SOK77P@kernel.org/
[3] https://git.kernel.org/pub/scm/linux/kernel/git/dakr/linux.git/log/?h=driver_override

Changes in v2:
  - Drop DEVICE_ATTR_DRIVER_OVERRIDE() and make driver_override a
    struct bus_type feature instead.
  - Add driver_override documentation in .../driver-model/binding.rst.
  - Move kfree(dev->driver_override.name) before release().
  - hwmon: axi-fan: Use NULL instead of dev_name() in
    devm_request_threaded_irq().

Danilo Krummrich (4):
  driver core: generalize driver_override in struct device
  docs: driver-model: document driver_override
  hwmon: axi-fan: don't use driver_override as IRQ name
  driver core: platform: use generic driver_override infrastructure

 .../driver-api/driver-model/binding.rst       | 48 +++++++++++++++
 arch/sh/drivers/platform_early.c              |  6 +-
 drivers/base/bus.c                            | 43 ++++++++++++-
 drivers/base/core.c                           |  2 +
 drivers/base/dd.c                             | 60 +++++++++++++++++++
 drivers/base/platform.c                       | 37 ++----------
 drivers/bus/simple-pm-bus.c                   |  4 +-
 drivers/clk/imx/clk-scu.c                     |  3 +-
 drivers/hwmon/axi-fan-control.c               |  2 +-
 drivers/slimbus/qcom-ngd-ctrl.c               |  6 +-
 include/linux/device.h                        | 54 +++++++++++++++++
 include/linux/device/bus.h                    |  4 ++
 include/linux/platform_device.h               |  5 --
 sound/soc/samsung/i2s.c                       |  6 +-
 14 files changed, 228 insertions(+), 52 deletions(-)


base-commit: 11439c4635edd669ae435eec308f4ab8a0804808
-- 
2.53.0