linux/drivers/i2c
Geert Uytterhoeven 1a50d9403f treewide: Fix probing of devices in DT overlays
When loading a DT overlay that creates a device, the device is not
probed, unless the DT overlay is unloaded and reloaded again.

After the recent refactoring to improve fw_devlink, it no longer depends
on the "compatible" property to identify which device tree nodes will
become struct devices.   fw_devlink now picks up dangling consumers
(consumers pointing to descendent device tree nodes of a device that
aren't converted to child devices) when a device is successfully bound
to a driver.  See __fw_devlink_pickup_dangling_consumers().

However, during DT overlay, a device's device tree node can have
sub-nodes added/removed without unbinding/rebinding the driver.  This
difference in behavior between the normal device instantiation and
probing flow vs. the DT overlay flow has a bunch of implications that
are pointed out elsewhere[1].  One of them is that the fw_devlink logic
to pick up dangling consumers is never exercised.

This patch solves the fw_devlink issue by marking all DT nodes added by
DT overlays with FWNODE_FLAG_NOT_DEVICE (fwnode that won't become
device), and by clearing the flag when a struct device is actually
created for the DT node.  This way, fw_devlink knows not to have
consumers waiting on these newly added DT nodes, and to propagate the
dependency to an ancestor DT node that has the corresponding struct
device.

Based on a patch by Saravana Kannan, which covered only platform and spi
devices.

[1] https://lore.kernel.org/r/CAGETcx_bkuFaLCiPrAWCPQz+w79ccDp6=9e881qmK=vx3hBMyg@mail.gmail.com

Fixes: 4a032827da ("of: property: Simplify of_link_to_phandle()")
Link: https://lore.kernel.org/r/CAGETcx_+rhHvaC_HJXGrr5_WAd2+k5f=rWYnkCZ6z5bGX-wj4w@mail.gmail.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C
Acked-by: Shawn Guo <shawnguo@kernel.org>
Acked-by: Saravana Kannan <saravanak@google.com>
Tested-by: Ivan Bornyakov <i.bornyakov@metrotek.ru>
Link: https://lore.kernel.org/r/e1fa546682ea4c8474ff997ab6244c5e11b6f8bc.1680182615.git.geert+renesas@glider.be
Signed-off-by: Rob Herring <robh@kernel.org>
2023-04-11 14:39:52 -05:00
..
algos i2c: algo: bit: use new macro to specifiy capabilities 2021-01-22 09:59:21 +01:00
busses Core got a new helper 'i2c_client_get_device_id', designware got some 2022-12-15 14:47:10 -08:00
muxes i2c: mux: reg: check return value after calling platform_get_resource() 2022-12-07 21:19:32 +01:00
i2c-boardinfo.c i2c: Remove support for dangling device properties 2021-04-10 21:43:02 +02:00
i2c-core-acpi.c More ACPI updates for 6.1-rc1 2022-10-10 13:28:06 -07:00
i2c-core-base.c Core got a new helper 'i2c_client_get_device_id', designware got some 2022-12-15 14:47:10 -08:00
i2c-core-of.c treewide: Fix probing of devices in DT overlays 2023-04-11 14:39:52 -05:00
i2c-core-slave.c i2c: add tracepoints for I2C slave events 2022-03-20 00:11:05 +01:00
i2c-core-smbus.c i2c: smbus: Check for parent device before dereference 2022-02-19 12:37:20 +01:00
i2c-core.h i2c: acpi: Use ACPI wake capability bit to set wake_irq 2022-10-04 15:41:12 +02:00
i2c-dev.c i2c: dev: Force case user pointers in compat_i2cdev_ioctl() 2022-04-15 23:30:59 +02:00
i2c-mux.c i2c: mux: harden i2c_mux_alloc() against integer overflows 2022-09-21 22:12:06 +02:00
i2c-slave-eeprom.c i2c: slave-eeprom: Convert to i2c's .probe_new() 2022-12-05 10:51:08 +01:00
i2c-slave-testunit.c i2c: Make remove callback return void 2022-08-16 12:46:26 +02:00
i2c-smbus.c drivers/i2c: use simple i2c probe 2022-12-05 10:37:20 +01:00
i2c-stub.c i2c: stub: remove definition of DEBUG 2021-01-17 13:00:10 +01:00
Kconfig i2c: add slave testunit driver 2020-09-21 11:02:17 +02:00
Makefile i2c: add slave testunit driver 2020-09-21 11:02:17 +02:00