linux/drivers/base
Saravana Kannan 2f8c3ae828 driver core: Add wait_for_init_devices_probe helper function
Some devices might need to be probed and bound successfully before the
kernel boot sequence can finish and move on to init/userspace. For
example, a network interface might need to be bound to be able to mount
a NFS rootfs.

With fw_devlink=on by default, some of these devices might be blocked
from probing because they are waiting on a optional supplier that
doesn't have a driver. While fw_devlink will eventually identify such
devices and unblock the probing automatically, it might be too late by
the time it unblocks the probing of devices. For example, the IP4
autoconfig might timeout before fw_devlink unblocks probing of the
network interface.

This function is available to temporarily try and probe all devices that
have a driver even if some of their suppliers haven't been added or
don't have drivers.

The drivers can then decide which of the suppliers are optional vs
mandatory and probe the device if possible. By the time this function
returns, all such "best effort" probes are guaranteed to be completed.
If a device successfully probes in this mode, we delete all fw_devlink
discovered dependencies of that device where the supplier hasn't yet
probed successfully because they have to be optional dependencies.

This also means that some devices that aren't needed for init and could
have waited for their optional supplier to probe (when the supplier's
module is loaded later on) would end up probing prematurely with limited
functionality.  So call this function only when boot would fail without
it.

Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20220601070707.3946847-5-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-10 15:57:54 +02:00
..
firmware_loader firmware_loader: enable XZ by default if compressed support is enabled 2022-06-03 15:46:03 -07:00
power PM: domains: Delete usage of driver_deferred_probe_check_state() 2022-06-10 15:57:54 +02:00
regmap regmap: Add missing map->bus check 2022-05-09 12:48:45 +01:00
test driver core: Simplify async probe test code by using ktime_ms_delta() 2021-12-29 10:57:22 +01:00
arch_numa.c mm: percpu: add generic pcpu_populate_pte() function 2022-01-20 08:52:52 +02:00
arch_topology.c arch_topology: Trace the update thermal pressure 2022-05-06 09:57:38 +02:00
attribute_container.c driver core: attribute_container: fix W=1 warnings 2021-05-14 13:37:10 +02:00
auxiliary.c Documentation/auxiliary_bus: Move the text into the code 2021-12-03 16:41:50 +01:00
base.h driver core: Add wait_for_init_devices_probe helper function 2022-06-10 15:57:54 +02:00
bus.c driver: base: fix UAF when driver_attach failed 2022-05-19 19:28:42 +02:00
cacheinfo.c cacheinfo: clear cache_leaves(cpu) in free_cache_attributes() 2021-07-21 17:29:40 +02:00
class.c block: remove genhd.h 2022-02-02 07:49:59 -07:00
component.c component: Add common helper for compare/release functions 2022-02-25 12:16:12 +01:00
container.c
core.c driver core: Add wait_for_init_devices_probe helper function 2022-06-10 15:57:54 +02:00
cpu.c sched/isolation: Use single feature type while referring to housekeeping cpumask 2022-02-16 15:57:55 +01:00
dd.c driver core: Add wait_for_init_devices_probe helper function 2022-06-10 15:57:54 +02:00
devcoredump.c devcoredump: remove contact information 2021-06-04 15:05:44 +02:00
devres.c devres: fix typos in comments 2022-03-18 14:30:12 +01:00
devtmpfs.c Driver core changes for 5.18-rc1 2022-03-28 12:41:28 -07:00
driver.c driver core: Extend deferred probe timeout on driver registration 2022-05-19 19:32:33 +02:00
firmware.c
hypervisor.c
init.c drivers/base/node: consolidate node device subsystem initialization in node_dev_init() 2022-03-22 15:57:10 -07:00
isa.c bus: Make remove callback return void 2021-07-21 11:53:42 +02:00
Kconfig devtmpfs: mount with noexec and nosuid 2021-12-30 13:54:42 +01:00
Makefile driver core: Add sysfs support for physical location of a device 2022-04-27 09:51:57 +02:00
map.c driver: base: Prefer unsigned int to bare use of unsigned 2021-07-21 17:30:09 +02:00
memory.c drivers/base/memory: fix an unlikely reference counting issue in __add_memory_block() 2022-04-28 23:16:19 -07:00
module.c
node.c drivers/base/node.c: fix compaction sysfs file leak 2022-04-28 23:16:06 -07:00
physical_location.c driver core: location: Add "back" as a possible output for panel 2022-05-19 19:28:32 +02:00
physical_location.h driver core: Add sysfs support for physical location of a device 2022-04-27 09:51:57 +02:00
pinctrl.c
platform-msi.c platform-msi: Simplify platform device MSI code 2021-12-16 22:22:19 +01:00
platform.c Driver core changes for 5.19-rc1 2022-06-03 11:48:47 -07:00
property.c USB / Thunderbolt changes for 5.19-rc1 2022-06-03 11:17:49 -07:00
soc.c base: soc: Make soc_device_match() simpler and easier to read 2022-03-18 14:28:07 +01:00
swnode.c software node: fix wrong node passed to find nargs_prop 2021-12-22 18:26:18 +01:00
syscore.c syscore: Use pm_pr_dbg() for syscore_{suspend,resume}() 2020-09-08 13:32:06 +02:00
topology.c topology: Fix up build warning in topology_is_visible() 2022-04-23 12:53:11 +02:00
trace.c devres: Enable trace events 2021-06-15 17:14:36 +02:00
trace.h devres: Enable trace events 2021-06-15 17:14:36 +02:00
transport_class.c