linux/drivers/base
John Stultz 35a672363a driver core: Ensure wait_for_device_probe() waits until the deferred_probe_timeout fires
In commit c8c43cee29 ("driver core: Fix
driver_deferred_probe_check_state() logic"), we set the default
driver_deferred_probe_timeout value to 30 seconds to allow for
drivers that are missing dependencies to have some time so that
the dependency may be loaded from userland after initcalls_done
is set.

However, Yoshihiro Shimoda reported that on his device that
expects to have unmet dependencies (due to "optional links" in
its devicetree), was failing to mount the NFS root.

In digging further, it seemed the problem was that while the
device properly probes after waiting 30 seconds for any missing
modules to load, the ip_auto_config() had already failed,
resulting in NFS to fail. This was due to ip_auto_config()
calling wait_for_device_probe() which doesn't wait for the
driver_deferred_probe_timeout to fire.

This patch tries to fix the issue by creating a waitqueue
for the driver_deferred_probe_timeout, and calling wait_event()
to make sure driver_deferred_probe_timeout is zero in
wait_for_device_probe() to make sure all the probing is
finished.

The downside to this solution is that kernel functionality that
uses wait_for_device_probe(), will block until the
driver_deferred_probe_timeout fires, regardless of if there is
any missing dependencies.

However, the previous patch reverts the default timeout value to
zero, so this side-effect will only affect users who specify a
driver_deferred_probe_timeout= value as a boot argument, where
the additional delay would be beneficial to allow modules to
load later during boot.

Thanks to Geert for chasing down that ip_auto_config was why NFS
was failing in this case!

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Rob Herring <robh@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Cc: Basil Eljuse <Basil.Eljuse@arm.com>
Cc: Ferry Toth <fntoth@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Anders Roxell <anders.roxell@linaro.org>
Cc: linux-pm@vger.kernel.org
Reported-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Fixes: c8c43cee29 ("driver core: Fix driver_deferred_probe_check_state() logic")
Signed-off-by: John Stultz <john.stultz@linaro.org>
Link: https://lore.kernel.org/r/20200422203245.83244-4-john.stultz@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28 17:57:13 +02:00
..
firmware_loader firmware_loader: revert removal of the fw_fallback_config export 2020-04-26 10:42:15 +02:00
power PM: sleep: core: Switch back to async_schedule_dev() 2020-04-22 16:36:18 +02:00
regmap regmap: fix writes to non incrementing registers 2020-01-21 17:16:26 +00:00
test Driver core changes for 5.6-rc1 2020-01-29 10:18:20 -08:00
arch_topology.c arm64 updates for 5.7: 2020-03-31 10:05:01 -07:00
attribute_container.c scsi: drivers: base: Support atomic version of attribute_container_device_trigger 2020-01-15 22:55:36 -05:00
base.h device.h: move devtmpfs prototypes out of the file 2019-12-16 10:10:18 +01:00
bus.c device.h: move 'struct bus' stuff out to device/bus.h 2019-12-16 10:11:12 +01:00
cacheinfo.c Driver Core and debugfs changes for 5.3-rc1 2019-07-12 12:24:03 -07:00
class.c device.h: move 'struct class' stuff out to device/class.h 2019-12-16 10:11:14 +01:00
component.c component: Silence bind error on -EPROBE_DEFER 2020-04-28 17:54:15 +02:00
container.c driver core: Remove redundant license text 2017-12-07 18:36:44 +01:00
core.c driver core: Fix handling of fw_devlink=permissive 2020-04-28 17:54:13 +02:00
cpu.c CPU (hotplug) updates: 2020-03-30 18:06:39 -07:00
dd.c driver core: Ensure wait_for_device_probe() waits until the deferred_probe_timeout fires 2020-04-28 17:57:13 +02:00
devcon.c Merge generic_lookup_helpers into usb-next 2019-09-03 17:11:07 +02:00
devcoredump.c devcoredump: fix typo in comment 2019-08-15 17:38:11 +02:00
devres.c drivers/base/devres: introduce devm_release_action() 2019-06-13 17:34:56 -10:00
devtmpfs.c Merge branch 'merge.nfs-fs_parse.1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-02-08 13:26:41 -08:00
driver.c device.h: move 'struct driver' stuff out to device/driver.h 2019-12-16 10:11:16 +01:00
firmware.c driver core: Remove redundant license text 2017-12-07 18:36:44 +01:00
hypervisor.c driver core: Remove redundant license text 2017-12-07 18:36:44 +01:00
init.c base: fix order of OF initialization 2018-07-07 17:54:29 +02:00
isa.c Merge 4.15-rc3 into driver-core-next 2017-12-11 08:50:05 +01:00
Kconfig kunit: building kunit as a module breaks allmodconfig 2020-01-10 14:36:37 -07:00
Makefile drivers: base: Introducing software nodes to the firmware node framework 2018-11-26 18:19:11 +01:00
map.c driver core: Remove redundant license text 2017-12-07 18:36:44 +01:00
memory.c mm/memory_hotplug: allow to specify a default online_type 2020-04-07 10:43:41 -07:00
module.c driver core: Remove redundant license text 2017-12-07 18:36:44 +01:00
node.c mm/sparse: rename pfn_present() to pfn_in_present_section() 2020-04-02 09:35:30 -07:00
pinctrl.c driver core: Remove redundant license text 2017-12-07 18:36:44 +01:00
platform-msi.c platform-msi: Free descriptors in platform_msi_domain_free() 2018-12-13 09:35:31 +00:00
platform.c driver core: platform: Initialize dma_parms for platform devices 2020-04-28 17:44:33 +02:00
property.c device property: Export fwnode_get_name() 2020-03-16 07:47:58 +01:00
soc.c base: soc: Handle custom soc information sysfs entries 2019-10-10 14:35:32 +02:00
swnode.c Revert "software node: Simplify software_node_release() function" 2020-03-04 22:31:44 +01:00
syscore.c treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively 2019-04-09 14:19:06 +02:00
topology.c topology: Create core_cpus and die_cpus sysfs attributes 2019-05-23 10:08:34 +02:00
transport_class.c scsi: drivers: base: Propagate errors through the transport component 2020-01-15 22:55:37 -05:00