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Author SHA1 Message Date
Linus Torvalds
55cb93fd24 Driver core changes for 6.13-rc1
Here is a small set of driver core changes for 6.13-rc1.
 
 Nothing major for this merge cycle, except for the 2 simple merge
 conflicts are here just to make life interesting.
 
 Included in here are:
   - sysfs core changes and preparations for more sysfs api cleanups that
     can come through all driver trees after -rc1 is out
   - fw_devlink fixes based on many reports and debugging sessions
   - list_for_each_reverse() removal, no one was using it!
   - last-minute seq_printf() format string bug found and fixed in many
     drivers all at once.
   - minor bugfixes and changes full details in the shortlog
 
 As mentioned above, there is 2 merge conflicts with your tree, one is
 where the file is removed (easy enough to resolve), the second is a
 build time error, that has been found in linux-next and the fix can be
 seen here:
 	https://lore.kernel.org/r/20241107212645.41252436@canb.auug.org.au
 
 Other than that, the changes here have been in linux-next with no other
 reported issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is a small set of driver core changes for 6.13-rc1.

  Nothing major for this merge cycle, except for the two simple merge
  conflicts are here just to make life interesting.

  Included in here are:

   - sysfs core changes and preparations for more sysfs api cleanups
     that can come through all driver trees after -rc1 is out

   - fw_devlink fixes based on many reports and debugging sessions

   - list_for_each_reverse() removal, no one was using it!

   - last-minute seq_printf() format string bug found and fixed in many
     drivers all at once.

   - minor bugfixes and changes full details in the shortlog"

* tag 'driver-core-6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (35 commits)
  Fix a potential abuse of seq_printf() format string in drivers
  cpu: Remove spurious NULL in attribute_group definition
  s390/con3215: Remove spurious NULL in attribute_group definition
  perf: arm-ni: Remove spurious NULL in attribute_group definition
  driver core: Constify bin_attribute definitions
  sysfs: attribute_group: allow registration of const bin_attribute
  firmware_loader: Fix possible resource leak in fw_log_firmware_info()
  drivers: core: fw_devlink: Fix excess parameter description in docstring
  driver core: class: Correct WARN() message in APIs class_(for_each|find)_device()
  cacheinfo: Use of_property_present() for non-boolean properties
  cdx: Fix cdx_mmap_resource() after constifying attr in ->mmap()
  drivers: core: fw_devlink: Make the error message a bit more useful
  phy: tegra: xusb: Set fwnode for xusb port devices
  drm: display: Set fwnode for aux bus devices
  driver core: fw_devlink: Stop trying to optimize cycle detection logic
  driver core: Constify attribute arguments of binary attributes
  sysfs: bin_attribute: add const read/write callback variants
  sysfs: implement all BIN_ATTR_* macros in terms of __BIN_ATTR()
  sysfs: treewide: constify attribute callback of bin_attribute::llseek()
  sysfs: treewide: constify attribute callback of bin_attribute::mmap()
  ...
2024-11-29 11:43:29 -08:00
Linus Torvalds
f2ef39727a spi: Updates for v6.13
The only real core work we've got this time around is the completion of
 the transition to the new host/target naming for the core APIs, Kconfig
 still needs doing but that's a lot less invasive.  Otherwise the big
 changes are the new drivers that have been added:
 
  - Completion of the conversion to spi_alloc_host()/_target() and
    removal of the old naming.
  - Cleanups for Rockchip drivers, these brought in a new logging helper
    in the driver core for warnings during probe.
  - Support for configuration of the word delay via spidev_test.
  - Support for AMD HID2 controllers, Apple SPI controller and Realtek
    SPI-NAND controllers.
 
 The Rockchip cleanups
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Merge tag 'spi-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi updates from Mark Brown:
 "The only real core work we've got this time around is the completion
  of the transition to the new host/target naming for the core APIs,
  Kconfig still needs doing but that's a lot less invasive.

  Otherwise the big changes are the new drivers that have been added:

   - Completion of the conversion to spi_alloc_host()/_target() and
     removal of the old naming.

   - Cleanups for Rockchip drivers, these brought in a new logging
     helper in the driver core for warnings during probe.

   - Support for configuration of the word delay via spidev_test.

   - Support for AMD HID2 controllers, Apple SPI controller and Realtek
     SPI-NAND controllers"

* tag 'spi-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (58 commits)
  spi: imx: support word delay
  spi: imx: pass struct spi_transfer to prepare_transfer()
  spi: cs42l43: Add GPIO speaker id support to the bridge configuration
  spi: Delete useless checks
  spi: apple: Remove unnecessary .owner for apple_spi_driver
  spi: spidev_test: add support for word delay
  spi: apple: Add driver for Apple SPI controller
  spi: dt-bindings: apple,spi: Add binding for Apple SPI controllers
  spi: Use of_property_present() for non-boolean properties
  spi: zynqmp-gqspi: Undo runtime PM changes at driver exit time​
  spi: spi-mem: rtl-snand: Correctly handle DMA transfers
  spi: tegra210-quad: Avoid shift-out-of-bounds
  spi: axi-spi-engine: Emit trace events for spi transfers
  dt-bindings: spi: sprd,sc9860-spi: convert to YAML
  spi: Replace deprecated PCI functions
  spi: dt-bindings: samsung: Add a compatible for samsung,exynos8895-spi
  spi: spi-mem: Add Realtek SPI-NAND controller
  dt-bindings: spi: Add realtek,rtl9301-snand
  spi: make class structs const
  spi: dt-bindings: brcm,bcm2835-aux-spi: Convert to dtschema
  ...
2024-11-20 12:23:06 -08:00
Amit Vadhavana
f841224f03 drivers: core: fw_devlink: Fix excess parameter description in docstring
Replace the parameter name 'con' with 'con_handle' in the docstring of
__fw_devlink_relax_cycles() to resolve the kernel-doc warning about an
excess parameter description.

Address the following warning:
./drivers/base/core.c:1994: warning: Excess function parameter 'con' description in '__fw_devlink_relax_cycles'

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/all/20241107223528.3781323e@canb.auug.org.au/
Signed-off-by: Amit Vadhavana <av2082000@gmail.com>
Link: https://lore.kernel.org/r/20241111165253.16672-1-av2082000@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-12 13:10:50 +01:00
Saravana Kannan
298c2af478 drivers: core: fw_devlink: Make the error message a bit more useful
It would make it easier to debugs issues similar to the ones
reported[1][2] recently where some devices didn't have the fwnode set.

[1] - https://lore.kernel.org/all/7b995947-4540-4b17-872e-e107adca4598@notapiano/
[2] - https://lore.kernel.org/all/20240910130019.35081-1-jonathanh@nvidia.com/

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20241024061347.1771063-4-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-05 14:03:27 +01:00
Saravana Kannan
bac3b10b78 driver core: fw_devlink: Stop trying to optimize cycle detection logic
In attempting to optimize fw_devlink runtime, I introduced numerous cycle
detection bugs by foregoing cycle detection logic under specific
conditions. Each fix has further narrowed the conditions for optimization.

It's time to give up on these optimization attempts and just run the cycle
detection logic every time fw_devlink tries to create a device link.

The specific bug report that triggered this fix involved a supplier fwnode
that never gets a device created for it. Instead, the supplier fwnode is
represented by the device that corresponds to an ancestor fwnode.

In this case, fw_devlink didn't do any cycle detection because the cycle
detection logic is only run when a device link is created between the
devices that correspond to the actual consumer and supplier fwnodes.

With this change, fw_devlink will run cycle detection logic even when
creating SYNC_STATE_ONLY proxy device links from a device that is an
ancestor of a consumer fwnode.

Reported-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Closes: https://lore.kernel.org/all/1a1ab663-d068-40fb-8c94-f0715403d276@ideasonboard.com/
Fixes: 6442d79d88 ("driver core: fw_devlink: Improve detection of overlapping cycles")
Cc: stable <stable@kernel.org>
Tested-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20241030171009.1853340-1-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-05 14:02:39 +01:00
Greg Kroah-Hartman
09fbb82f94 Merge 6.12-rc6 into driver-core-next
We need the driver-core fix/revert in here as well to build on top of.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-05 10:11:53 +01:00
Bartosz Golaszewski
6b8ab72415 driver core: constify devlink class
The devlink class object is never modified and can be made constant.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Acked-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20241014122849.118766-1-brgl@bgdev.pl
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-04 01:59:58 +01:00
Linus Torvalds
886b7e80ab Driver core revert fix for 6.12-rc6
Here is a single driver core revert for 6.12-rc6.  It reverts a change
 that came in -rc1 that was supposed to resolve a reported problem, but
 caused another one, so revert it for now so that we can get this all
 worked out properly in 6.13.
 
 The revert has been in linux-next all week with no reported issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-6.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core revert from Greg KH:
 "Here is a single driver core revert for 6.12-rc6. It reverts a change
  that came in -rc1 that was supposed to resolve a reported problem, but
  caused another one, so revert it for now so that we can get this all
  worked out properly in 6.13.

  The revert has been in linux-next all week with no reported issues"

* tag 'driver-core-6.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  Revert "driver core: Fix uevent_show() vs driver detach race"
2024-11-03 08:51:53 -10:00
Greg Kroah-Hartman
9a71892cbc Revert "driver core: Fix uevent_show() vs driver detach race"
This reverts commit 15fffc6a56.

This commit causes a regression, so revert it for now until it can come
back in a way that works for everyone.

Link: https://lore.kernel.org/all/172790598832.1168608.4519484276671503678.stgit@dwillia2-xfh.jf.intel.com/
Fixes: 15fffc6a56 ("driver core: Fix uevent_show() vs driver detach race")
Cc: stable <stable@kernel.org>
Cc: Ashish Sangwan <a.sangwan@samsung.com>
Cc: Namjae Jeon <namjae.jeon@samsung.com>
Cc: Dirk Behme <dirk.behme@de.bosch.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-29 01:23:43 +01:00
Dan Williams
101c268bd2 cxl/port: Fix use-after-free, permit out-of-order decoder shutdown
In support of investigating an initialization failure report [1],
cxl_test was updated to register mock memory-devices after the mock
root-port/bus device had been registered. That led to cxl_test crashing
with a use-after-free bug with the following signature:

    cxl_port_attach_region: cxl region3: cxl_host_bridge.0:port3 decoder3.0 add: mem0:decoder7.0 @ 0 next: cxl_switch_uport.0 nr_eps: 1 nr_targets: 1
    cxl_port_attach_region: cxl region3: cxl_host_bridge.0:port3 decoder3.0 add: mem4:decoder14.0 @ 1 next: cxl_switch_uport.0 nr_eps: 2 nr_targets: 1
    cxl_port_setup_targets: cxl region3: cxl_switch_uport.0:port6 target[0] = cxl_switch_dport.0 for mem0:decoder7.0 @ 0
1)  cxl_port_setup_targets: cxl region3: cxl_switch_uport.0:port6 target[1] = cxl_switch_dport.4 for mem4:decoder14.0 @ 1
    [..]
    cxld_unregister: cxl decoder14.0:
    cxl_region_decode_reset: cxl_region region3:
    mock_decoder_reset: cxl_port port3: decoder3.0 reset
2)  mock_decoder_reset: cxl_port port3: decoder3.0: out of order reset, expected decoder3.1
    cxl_endpoint_decoder_release: cxl decoder14.0:
    [..]
    cxld_unregister: cxl decoder7.0:
3)  cxl_region_decode_reset: cxl_region region3:
    Oops: general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6bc3: 0000 [#1] PREEMPT SMP PTI
    [..]
    RIP: 0010:to_cxl_port+0x8/0x60 [cxl_core]
    [..]
    Call Trace:
     <TASK>
     cxl_region_decode_reset+0x69/0x190 [cxl_core]
     cxl_region_detach+0xe8/0x210 [cxl_core]
     cxl_decoder_kill_region+0x27/0x40 [cxl_core]
     cxld_unregister+0x5d/0x60 [cxl_core]

At 1) a region has been established with 2 endpoint decoders (7.0 and
14.0). Those endpoints share a common switch-decoder in the topology
(3.0). At teardown, 2), decoder14.0 is the first to be removed and hits
the "out of order reset case" in the switch decoder. The effect though
is that region3 cleanup is aborted leaving it in-tact and
referencing decoder14.0. At 3) the second attempt to teardown region3
trips over the stale decoder14.0 object which has long since been
deleted.

The fix here is to recognize that the CXL specification places no
mandate on in-order shutdown of switch-decoders, the driver enforces
in-order allocation, and hardware enforces in-order commit. So, rather
than fail and leave objects dangling, always remove them.

In support of making cxl_region_decode_reset() always succeed,
cxl_region_invalidate_memregion() failures are turned into warnings.
Crashing the kernel is ok there since system integrity is at risk if
caches cannot be managed around physical address mutation events like
CXL region destruction.

A new device_for_each_child_reverse_from() is added to cleanup
port->commit_end after all dependent decoders have been disabled. In
other words if decoders are allocated 0->1->2 and disabled 1->2->0 then
port->commit_end only decrements from 2 after 2 has been disabled, and
it decrements all the way to zero since 1 was disabled previously.

Link: http://lore.kernel.org/20241004212504.1246-1-gourry@gourry.net [1]
Cc: stable@vger.kernel.org
Fixes: 176baefb2e ("cxl/hdm: Commit decoder state to hardware")
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Zijun Hu <quic_zijuhu@quicinc.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: https://patch.msgid.link/172964782781.81806.17902885593105284330.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
2024-10-25 16:07:03 -05:00
Dragan Simic
36e69b1607
driver core: Add device probe log helper dev_warn_probe()
Some drivers can still provide their functionality to a certain extent
even when some of their resource acquisitions eventually fail.  In such
cases, emitting errors isn't the desired action, but warnings should be
emitted instead.

To solve this, introduce dev_warn_probe() as a new device probe log helper,
which behaves identically as the already existing dev_err_probe(), while it
produces warnings instead of errors.  The intended use is with the resources
that are actually optional for a particular driver.

While there, copyedit the kerneldoc for dev_err_probe() a bit, to simplify
its wording a bit, and reuse it as the kerneldoc for dev_warn_probe(), with
the necessary wording adjustments, of course.

Signed-off-by: Dragan Simic <dsimic@manjaro.org>
Tested-by: Hélène Vulquin <oss@helene.moe>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/2be0a28538bb2a3d1bcc91e2ca1f2d0dc09146d9.1727601608.git.dsimic@manjaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2024-10-08 18:41:06 +01:00
Greg Kroah-Hartman
eb46cb321f Revert "driver core: don't always lock parent in shutdown"
This reverts commit ba6353748e.

The series is being reverted before -rc1 as there are still reports of
lockups on shutdown, so it's not quite ready for "prime time."

Reported-by: Andrey Skvortsov <andrej.skvortzov@gmail.com>
Link: https://lore.kernel.org/r/ZvMkkhyJrohaajuk@skv.local
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Jeffery <djeffery@redhat.com>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Laurence Oberman <loberman@redhat.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Stuart Hayes <stuart.w.hayes@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-25 11:01:34 +02:00
Greg Kroah-Hartman
56d16d44fe Revert "driver core: separate function to shutdown one device"
This reverts commit 95dc756525.

The series is being reverted before -rc1 as there are still reports of
lockups on shutdown, so it's not quite ready for "prime time."

Reported-by: Andrey Skvortsov <andrej.skvortzov@gmail.com>
Link: https://lore.kernel.org/r/ZvMkkhyJrohaajuk@skv.local
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Jeffery <djeffery@redhat.com>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Laurence Oberman <loberman@redhat.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Stuart Hayes <stuart.w.hayes@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-25 11:01:30 +02:00
Greg Kroah-Hartman
2efddb5575 Revert "driver core: shut down devices asynchronously"
This reverts commit 8064952c65.

The series is being reverted before -rc1 as there are still reports of
lockups on shutdown, so it's not quite ready for "prime time."

Reported-by: Andrey Skvortsov <andrej.skvortzov@gmail.com>
Link: https://lore.kernel.org/r/ZvMkkhyJrohaajuk@skv.local
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Jeffery <djeffery@redhat.com>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Laurence Oberman <loberman@redhat.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Stuart Hayes <stuart.w.hayes@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-25 11:01:27 +02:00
Greg Kroah-Hartman
e11daafdbf Revert "driver core: fix async device shutdown hang"
This reverts commit 4f2c346e62.

The series is being reverted before -rc1 as there are still reports of
lockups on shutdown, so it's not quite ready for "prime time."

Reported-by: Andrey Skvortsov <andrej.skvortzov@gmail.com>
Link: https://lore.kernel.org/r/ZvMkkhyJrohaajuk@skv.local
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Jeffery <djeffery@redhat.com>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Laurence Oberman <loberman@redhat.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Stuart Hayes <stuart.w.hayes@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-25 11:01:20 +02:00
Stuart Hayes
4f2c346e62 driver core: fix async device shutdown hang
Modify device_shutdown() so that supplier devices do not wait for
consumer devices to be shut down first when the devlink is sync state
only, since the consumer is not dependent on the supplier in this case.

Without this change, a circular dependency could hang the system.

Fixes: 8064952c65 ("driver core: shut down devices asynchronously")
Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20240919043143.1194950-1-stuart.w.hayes@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-21 11:14:52 +02:00
Zijun Hu
903c44939a driver core: Make parameter check consistent for API cluster device_(for_each|find)_child()
The following API cluster takes the same type parameter list, but do not
have consistent parameter check as shown below.

device_for_each_child(struct device *parent, ...)  // check (!parent->p)
device_for_each_child_reverse(struct device *parent, ...) // same as above
device_find_child(struct device *parent, ...)      // check (!parent)

Fixed by using consistent check (!parent || !parent->p) which covers
both existing checks for the cluster.

Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20240824-const_dfc_prepare-v3-1-32127ea32bba@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-03 13:14:59 +02:00
Stuart Hayes
8064952c65 driver core: shut down devices asynchronously
Add code to allow asynchronous shutdown of devices, ensuring that each
device is shut down before its parents & suppliers.

Only devices with drivers that have async_shutdown_enable enabled will be
shut down asynchronously.

This can dramatically reduce system shutdown/reboot time on systems that
have multiple devices that take many seconds to shut down (like certain
NVMe drives). On one system tested, the shutdown time went from 11 minutes
without this patch to 55 seconds with the patch.

Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Signed-off-by: David Jeffery <djeffery@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Tested-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20240822202805.6379-4-stuart.w.hayes@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-03 13:06:43 +02:00
Stuart Hayes
95dc756525 driver core: separate function to shutdown one device
Make a separate function for the part of device_shutdown() that does the
shutown for a single device.  This is in preparation for making device
shutdown asynchronous.

Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Signed-off-by: David Jeffery <djeffery@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Tested-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20240822202805.6379-3-stuart.w.hayes@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-03 13:05:08 +02:00
Stuart Hayes
ba6353748e driver core: don't always lock parent in shutdown
Don't lock a parent device unless it is needed in device_shutdown. This
is in preparation for making device shutdown asynchronous, when it will
be needed to allow children of a common parent to shut down
simultaneously.

Signed-off-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Signed-off-by: David Jeffery <djeffery@redhat.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Tested-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20240822202805.6379-2-stuart.w.hayes@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-03 13:05:08 +02:00
Zijun Hu
a169a663bf driver core: class: Check namespace relevant parameters in class_register()
Device class has two namespace relevant fields which are usually
associated by the following usage:

struct class {
	...
	const struct kobj_ns_type_operations *ns_type;
	const void *(*namespace)(const struct device *dev);
	...
}
if (dev->class && dev->class->ns_type)
	dev->class->namespace(dev);

(1) The usage looks weird since it checks @ns_type but calls namespace()
(2) The usage implies both fields have dependency but their dependency
    is not currently enforced yet.

It is found for all existing class definitions that the other filed is
also assigned once one is assigned in current kernel tree.

Fixed by enforcing above existing dependency that both fields are required
for a device class to support namespace via parameter checks.

Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20240822-class_fix-v1-1-2a6d38ba913a@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-03 13:00:20 +02:00
Yuesong Li
4a74f22386 driver:base:core: Adding a "Return:" line in comment for device_link_add()
The original document doesn't explain the return value directly which
leads to confusing in error checking.

You can find the reason here:
Link: https://lore.kernel.org/all/1d4c39e109bcf288d5900670e024a315.sboyd@kernel.org/

Signed-off-by: Yuesong Li <liyuesong@vivo.com>
Link: https://lore.kernel.org/r/20240821040432.4049183-1-liyuesong@vivo.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-03 12:59:17 +02:00
Andy Shevchenko
888f67e621 driver core: Use 2-argument strscpy()
Use 2-argument strscpy(), which is not only shorter but also provides
an additional check that destination buffer is an array.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240821154839.604259-6-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-22 15:37:38 +08:00
Andy Shevchenko
d1363030d8 driver core: Make use of returned value of dev_err_probe()
Instead of assigning ret explicitly to the same value that is supplied
to dev_err_probe(), make use  of returned value of the latter.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240821154839.604259-5-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-22 15:37:38 +08:00
Andy Shevchenko
adcae2048d driver core: Use guards for simple mutex locks
Guards can help to make the code more readable. So use it wherever they
do so.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240821154839.604259-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-22 15:37:38 +08:00
Andy Shevchenko
a355a4655e driver core: Use kasprintf() instead of fixed buffer formatting
Improve readability and maintainability by replacing a hardcoded string
allocation and formatting by the use of the kasprintf() helper.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240821154839.604259-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-22 15:37:38 +08:00
Andy Shevchenko
d11f2a1ab8 driver core: Sort headers
Sort the headers in alphabetic order in order to ease
the maintenance for this part.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240821154839.604259-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-22 15:37:38 +08:00
Greg Kroah-Hartman
0c80bdfc9a Merge 6.11-rc3 into driver-core-next
We need the driver core fixes in here as well to build on top of.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-12 18:46:07 +02:00
Zijun Hu
0314647dec driver core: Remove unused parameter for virtual_device_parent()
Function struct kobject *virtual_device_parent(struct device *dev)
does not use its parameter @dev, and the kobject returned also has
nothing deal with specific device, so remove the unused parameter.

Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20240725-virtual_kobj_fix-v1-1-36335cae4544@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-31 14:55:13 +02:00
Zijun Hu
6d8249ac29 driver core: Fix error handling in driver API device_rename()
For class-device, device_rename() failure maybe cause unexpected link name
within its class folder as explained below:

/sys/class/.../old_name -> /sys/devices/.../old_name
device_rename(..., new_name) and failed
/sys/class/.../new_name -> /sys/devices/.../old_name

Fixed by undoing renaming link if renaming kobject failed.

Fixes: f349cf3473 ("driver core: Implement ns directory support for device classes.")
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20240722-device_rename_fix-v2-1-77de1a6c6495@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-31 14:54:47 +02:00
Zijun Hu
4ea5e9deda driver core: Fix size calculation of symlink name for devlink_(add|remove)_symlinks()
devlink_(add|remove)_symlinks() kzalloc() memory to save symlink name
for both supplier and consumer, but do not explicitly take into account
consumer's prefix "consumer:", so cause disadvantages listed below:
1) it seems wrong for the algorithm to calculate memory size
2) readers maybe need to count characters one by one of both prefix
   strings to confirm calculated memory size
3) it is relatively easy to introduce new bug if either prefix string
   is modified in future
solved by taking into account consumer's prefix as well.

Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20240712-devlink_fix-v3-1-fa1c5172ffc7@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-31 14:54:08 +02:00
Dan Williams
15fffc6a56 driver core: Fix uevent_show() vs driver detach race
uevent_show() wants to de-reference dev->driver->name. There is no clean
way for a device attribute to de-reference dev->driver unless that
attribute is defined via (struct device_driver).dev_groups. Instead, the
anti-pattern of taking the device_lock() in the attribute handler risks
deadlocks with code paths that remove device attributes while holding
the lock.

This deadlock is typically invisible to lockdep given the device_lock()
is marked lockdep_set_novalidate_class(), but some subsystems allocate a
local lockdep key for @dev->mutex to reveal reports of the form:

 ======================================================
 WARNING: possible circular locking dependency detected
 6.10.0-rc7+ #275 Tainted: G           OE    N
 ------------------------------------------------------
 modprobe/2374 is trying to acquire lock:
 ffff8c2270070de0 (kn->active#6){++++}-{0:0}, at: __kernfs_remove+0xde/0x220

 but task is already holding lock:
 ffff8c22016e88f8 (&cxl_root_key){+.+.}-{3:3}, at: device_release_driver_internal+0x39/0x210

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #1 (&cxl_root_key){+.+.}-{3:3}:
        __mutex_lock+0x99/0xc30
        uevent_show+0xac/0x130
        dev_attr_show+0x18/0x40
        sysfs_kf_seq_show+0xac/0xf0
        seq_read_iter+0x110/0x450
        vfs_read+0x25b/0x340
        ksys_read+0x67/0xf0
        do_syscall_64+0x75/0x190
        entry_SYSCALL_64_after_hwframe+0x76/0x7e

 -> #0 (kn->active#6){++++}-{0:0}:
        __lock_acquire+0x121a/0x1fa0
        lock_acquire+0xd6/0x2e0
        kernfs_drain+0x1e9/0x200
        __kernfs_remove+0xde/0x220
        kernfs_remove_by_name_ns+0x5e/0xa0
        device_del+0x168/0x410
        device_unregister+0x13/0x60
        devres_release_all+0xb8/0x110
        device_unbind_cleanup+0xe/0x70
        device_release_driver_internal+0x1c7/0x210
        driver_detach+0x47/0x90
        bus_remove_driver+0x6c/0xf0
        cxl_acpi_exit+0xc/0x11 [cxl_acpi]
        __do_sys_delete_module.isra.0+0x181/0x260
        do_syscall_64+0x75/0x190
        entry_SYSCALL_64_after_hwframe+0x76/0x7e

The observation though is that driver objects are typically much longer
lived than device objects. It is reasonable to perform lockless
de-reference of a @driver pointer even if it is racing detach from a
device. Given the infrequency of driver unregistration, use
synchronize_rcu() in module_remove_driver() to close any potential
races.  It is potentially overkill to suffer synchronize_rcu() just to
handle the rare module removal racing uevent_show() event.

Thanks to Tetsuo Handa for the debug analysis of the syzbot report [1].

Fixes: c0a40097f0 ("drivers: core: synchronize really_probe() and dev_uevent()")
Reported-by: syzbot+4762dd74e32532cda5ff@syzkaller.appspotmail.com
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Closes: http://lore.kernel.org/5aa5558f-90a4-4864-b1b1-5d6784c5607d@I-love.SAKURA.ne.jp [1]
Link: http://lore.kernel.org/669073b8ea479_5fffa294c1@dwillia2-xfh.jf.intel.com.notmuch
Cc: stable@vger.kernel.org
Cc: Ashish Sangwan <a.sangwan@samsung.com>
Cc: Namjae Jeon <namjae.jeon@samsung.com>
Cc: Dirk Behme <dirk.behme@de.bosch.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/172081332794.577428.9738802016494057132.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-31 14:41:44 +02:00
Uwe Kleine-König
2f3cfd2f4b driver core: Make dev_err_probe() silent for -ENOMEM
For an out-of-memory error there should be no additional output. Adapt
dev_err_probe() to not emit the error message when err is -ENOMEM.
This simplifies handling errors that might among others be -ENOMEM.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/3d1e308d45cddf67749522ca42d83f5b4f0b9634.1718311756.git.u.kleine-koenig@baylibre.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-20 12:48:09 +02:00
Dirk Behme
c0a40097f0 drivers: core: synchronize really_probe() and dev_uevent()
Synchronize the dev->driver usage in really_probe() and dev_uevent().
These can run in different threads, what can result in the following
race condition for dev->driver uninitialization:

Thread #1:
==========

really_probe() {
...
probe_failed:
...
device_unbind_cleanup(dev) {
    ...
    dev->driver = NULL;   // <= Failed probe sets dev->driver to NULL
    ...
    }
...
}

Thread #2:
==========

dev_uevent() {
...
if (dev->driver)
      // If dev->driver is NULLed from really_probe() from here on,
      // after above check, the system crashes
      add_uevent_var(env, "DRIVER=%s", dev->driver->name);
...
}

really_probe() holds the lock, already. So nothing needs to be done
there. dev_uevent() is called with lock held, often, too. But not
always. What implies that we can't add any locking in dev_uevent()
itself. So fix this race by adding the lock to the non-protected
path. This is the path where above race is observed:

 dev_uevent+0x235/0x380
 uevent_show+0x10c/0x1f0  <= Add lock here
 dev_attr_show+0x3a/0xa0
 sysfs_kf_seq_show+0x17c/0x250
 kernfs_seq_show+0x7c/0x90
 seq_read_iter+0x2d7/0x940
 kernfs_fop_read_iter+0xc6/0x310
 vfs_read+0x5bc/0x6b0
 ksys_read+0xeb/0x1b0
 __x64_sys_read+0x42/0x50
 x64_sys_call+0x27ad/0x2d30
 do_syscall_64+0xcd/0x1d0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Similar cases are reported by syzkaller in

https://syzkaller.appspot.com/bug?extid=ffa8143439596313a85a

But these are regarding the *initialization* of dev->driver

dev->driver = drv;

As this switches dev->driver to non-NULL these reports can be considered
to be false-positives (which should be "fixed" by this commit, as well,
though).

The same issue was reported and tried to be fixed back in 2015 in

https://lore.kernel.org/lkml/1421259054-2574-1-git-send-email-a.sangwan@samsung.com/

already.

Fixes: 239378f16a ("Driver core: add uevent vars for devices of a class")
Cc: stable <stable@kernel.org>
Cc: syzbot+ffa8143439596313a85a@syzkaller.appspotmail.com
Cc: Ashish Sangwan <a.sangwan@samsung.com>
Cc: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
Link: https://lore.kernel.org/r/20240513050634.3964461-1-dirk.behme@de.bosch.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-04 18:14:51 +02:00
Greg Kroah-Hartman
9711873506 driver core: remove devm_device_add_groups()
There is no more in-kernel users of this function, and no driver should
ever be using it, so remove it from the kernel.

Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230704131715.44454-8-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-04 15:53:36 +02:00
Lukas Wunner
3cc50d07be driver core: Add device_show_string() helper for sysfs attributes
For drivers wishing to expose an unsigned long, int or bool at a static
memory location in sysfs, the driver core provides ready-made helpers
such as device_show_ulong() to be used as ->show() callback.

Some drivers need to expose a string and so far they all provide their
own ->show() implementation.  arch/powerpc/perf/hv-24x7.c went so far
as to create a device_show_string() helper but kept it private.

Make it public for reuse by other drivers.  The pattern seems to be
sufficiently frequent to merit a public helper.

Add a DEVICE_STRING_ATTR_RO() macro in line with the existing
DEVICE_ULONG_ATTR() and similar macros to ease declaration of string
attributes.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/2e3eaaf2600bb55c0415c23ba301e809403a7aa2.1713608122.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-05-04 17:37:03 +02:00
Greg Kroah-Hartman
e5019b1423 Merge 6.9-rc5 into driver-core-next
We want the kernfs fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-23 13:27:43 +02:00
Bjorn Helgaas
0bb322be5d driver core: Remove unused platform_notify, platform_notify_remove
The "platform_notify" and "platform_notify_remove" hooks have been unused
since 00ba9357d1 ("ARM: ixp4xx: Drop custom DMA coherency and bouncing").

Remove "platform_notify" and "platform_notify_remove".  No functional
change intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20240325221409.1457036-1-helgaas@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-03-27 08:01:12 +01:00
Herve Codina
0462c56c29 driver core: Introduce device_link_wait_removal()
The commit 80dd33cf72 ("drivers: base: Fix device link removal")
introduces a workqueue to release the consumer and supplier devices used
in the devlink.
In the job queued, devices are release and in turn, when all the
references to these devices are dropped, the release function of the
device itself is called.

Nothing is present to provide some synchronisation with this workqueue
in order to ensure that all ongoing releasing operations are done and
so, some other operations can be started safely.

For instance, in the following sequence:
  1) of_platform_depopulate()
  2) of_overlay_remove()

During the step 1, devices are released and related devlinks are removed
(jobs pushed in the workqueue).
During the step 2, OF nodes are destroyed but, without any
synchronisation with devlink removal jobs, of_overlay_remove() can raise
warnings related to missing of_node_put():
  ERROR: memory leak, expected refcount 1 instead of 2

Indeed, the missing of_node_put() call is going to be done, too late,
from the workqueue job execution.

Introduce device_link_wait_removal() to offer a way to synchronize
operations waiting for the end of devlink removals (i.e. end of
workqueue jobs).
Also, as a flushing operation is done on the workqueue, the workqueue
used is moved from a system-wide workqueue to a local one.

Cc: stable@vger.kernel.org
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Reviewed-by: Saravana Kannan <saravanak@google.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20240325152140.198219-2-herve.codina@bootlin.com
Signed-off-by: Rob Herring <robh@kernel.org>
2024-03-26 15:32:32 -05:00
Saravana Kannan
b7e1241d8f driver core: Add FWLINK_FLAG_IGNORE to completely ignore a fwnode link
A fwnode link between specific supplier-consumer fwnodes can be added
multiple times for multiple reasons. If that dependency doesn't exist,
deleting the fwnode link once doesn't guarantee that it won't get created
again.

So, add FWLINK_FLAG_IGNORE flag to mark a fwnode link as one that needs to
be completely ignored. Since a fwnode link's flags is an OR of all the
flags passed to all the fwnode_link_add() calls to create that specific
fwnode link, the FWLINK_FLAG_IGNORE flag is preserved and can be used to
mark a fwnode link as on that need to be completely ignored until it is
deleted.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Acked-by: "Rafael J. Wysocki" <rafael@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20240305050458.1400667-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-03-07 22:10:01 +00:00
Saravana Kannan
75cde56a5b driver core: Adds flags param to fwnode_link_add()
Allow the callers to set fwnode link flags when adding fwnode links.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Acked-by: "Rafael J. Wysocki" <rafael@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20240305050458.1400667-2-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-03-07 22:10:01 +00:00
Andy Shevchenko
1c4002aeab driver core: Move fw_devlink stuff to where it belongs
A few APIs, i.e. fwnode_is_ancestor_of(), fwnode_get_next_parent_dev(),
and get_dev_from_fwnode(), that belong specifically to the fw_devlink APIs,
may be static, but they are not.

Resolve this mess by moving them to the driver/base/core where the all
users are being resided and make static.

No functional changes intended.

Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: "Rafael J. Wysocki" <rafael@kernel.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240301180138.271590-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-03-07 22:07:22 +00:00
Saravana Kannan
6e7ad1aebb driver core: fw_devlink: Improve logs for cycle detection
The links in a cycle are not all logged in a consistent manner or not
logged at all. Make them consistent by adding a "cycle:" string and log all
the link in the cycles (even the child ==> parent dependency) so that it's
easier to debug cycle detection code. Also, mark the start and end of a
cycle so it's easy to tell when multiple cycles are logged back to back.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Tested-by: Xu Yang <xu.yang_2@nxp.com>
Link: https://lore.kernel.org/r/20240202095636.868578-4-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-02 07:12:33 -08:00
Saravana Kannan
6442d79d88 driver core: fw_devlink: Improve detection of overlapping cycles
fw_devlink can detect most overlapping/intersecting cycles. However it was
missing a few corner cases because of an incorrect optimization logic that
tries to avoid repeating cycle detection for devices that are already
marked as part of a cycle.

Here's an example provided by Xu Yang (edited for clarity):

                    usb
                  +-----+
   tcpc           |     |
  +-----+         |  +--|
  |     |----------->|EP|
  |--+  |         |  +--|
  |EP|<-----------|     |
  |--+  |         |  B  |
  |     |         +-----+
  |  A  |            |
  +-----+            |
     ^     +-----+   |
     |     |     |   |
     +-----|  C  |<--+
           |     |
           +-----+
           usb-phy

Node A (tcpc) will be populated as device 1-0050.
Node B (usb) will be populated as device 38100000.usb.
Node C (usb-phy) will be populated as device 381f0040.usb-phy.

The description below uses the notation:
consumer --> supplier
child ==> parent

1. Node C is populated as device C. No cycles detected because cycle
   detection is only run when a fwnode link is converted to a device link.

2. Node B is populated as device B. As we convert B --> C into a device
   link we run cycle detection and find and mark the device link/fwnode
   link cycle:
   C--> A --> B.EP ==> B --> C

3. Node A is populated as device A. As we convert C --> A into a device
   link, we see it's already part of a cycle (from step 2) and don't run
   cycle detection. Thus we miss detecting the cycle:
   A --> B.EP ==> B --> A.EP ==> A

Looking at it another way, A depends on B in one way:
A --> B.EP ==> B

But B depends on A in two ways and we only detect the first:
B --> C --> A
B --> A.EP ==> A

To detect both of these, we remove the incorrect optimization attempt in
step 3 and run cycle detection even if the fwnode link from which the
device link is being created has already been marked as part of a cycle.

Reported-by: Xu Yang <xu.yang_2@nxp.com>
Closes: https://lore.kernel.org/lkml/DU2PR04MB8822693748725F85DC0CB86C8C792@DU2PR04MB8822.eurprd04.prod.outlook.com/
Fixes: 3fb16866b5 ("driver core: fw_devlink: Make cycle detection more robust")
Signed-off-by: Saravana Kannan <saravanak@google.com>
Tested-by: Xu Yang <xu.yang_2@nxp.com>
Link: https://lore.kernel.org/r/20240202095636.868578-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-02 07:12:33 -08:00
Saravana Kannan
7fddac12c3 driver core: Fix device_link_flag_is_sync_state_only()
device_link_flag_is_sync_state_only() correctly returns true on the flags
of an existing device link that only implements sync_state() functionality.
However, it incorrectly and confusingly returns false if it's called with
DL_FLAG_SYNC_STATE_ONLY.

This bug doesn't manifest in any of the existing calls to this function,
but fix this confusing behavior to avoid future bugs.

Fixes: 67cad5c670 ("driver core: fw_devlink: Add DL_FLAG_CYCLE support to device links")
Signed-off-by: Saravana Kannan <saravanak@google.com>
Tested-by: Xu Yang <xu.yang_2@nxp.com>
Link: https://lore.kernel.org/r/20240202095636.868578-2-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-02 07:12:33 -08:00
Uwe Kleine-König
532888a595 driver core: Better advertise dev_err_probe()
Describing the usage of dev_err_probe() as being (only?) "deemed
acceptable" has a bad connotation. In fact dev_err_probe() fulfills
three tasks:

 - handling of EPROBE_DEFER (even more than degrading to dev_dbg())
 - symbolic output of the error code
 - return err for compact error code paths

Advertise these better and claim the usage to be "fine" to get rid of
the bad connotation.

Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20231215174540.2438601-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15 18:54:18 +01:00
Saravana Kannan
055467378b driver core: Enable fw_devlink=rpm by default
fw_devlink=on has stabilized and is working correctly. Let's start using
device links created by fw_devlink to also enforce runtime PM ordering.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20231113220948.80089-1-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-07 11:35:26 +09:00
Greg Kroah-Hartman
eec4954b81 driver core: make device_is_dependent() static
The function device_is_dependent() is only called by the driver core
internally and should not, at this time, be called by anyone else
outside of it, so mark it as static so as not to give driver authors the
wrong idea.

Cc: Saravana Kannan <saravanak@google.com>
Acked-by: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/2023112815-faculty-thud-add8@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 20:14:25 +00:00
Andy Shevchenko
f1ac370cdd driver core: Add missing parameter description to __fwnode_link_add()
The kernel documentation validator is not happy with:

  drivers/base/core.c:67: warning: Function parameter or member 'flags' not described in '__fwnode_link_add'

Add missing parameter description.

Fixes: 6a6dfdf8b3 ("driver core: fw_devlink: Allow marking a fwnode link as being part of a cycle")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230919195048.3197551-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-10-05 13:11:35 +02:00
Andy Shevchenko
fd6f7ad2fd driver core: return an error when dev_set_name() hasn't happened
The commit d21fdd07ce ("driver core: Return proper error code when
dev_set_name() fails") rewrote the logic of handling the dev_set_name()
error codes, but missed the point that initially set error value to
-EINVAL might be rewritten and hence the error path can't be triggered
at some circumstances. To fix this, make sure that error variable is
set to -EINVAL when other conditionals are false.

Reported-by: syzbot+bdfb03b1ec8b342c12cb@syzkaller.appspotmail.com
Fixes: d21fdd07ce ("driver core: Return proper error code when dev_set_name() fails")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230828145824.3895288-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-09-12 15:54:44 +02:00