drivers: base: component: add function to query the bound status

The component helpers already expose the bound status in debugfs, but at
times it might be necessary to also check that state in the

drivers: base: component: add function to query the bound status

The component helpers already expose the bound status in debugfs, but at
times it might be necessary to also check that state in the kernel and
act differently depending on the result.

For example the shutdown handler of a drm-driver might need to stop
a whole output pipeline if the drm device is up and running, but may
run into problems if that drm-device has never been set up before,
for example because the binding deferred.

So add a little helper that returns the bound status for a componet
device.

Acked-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Heiko Stuebner <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

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drivers: base: component: Add debug message for unbind

Like when binding component, add a debug message to the unbinding case
to make it easy to track the lifecycle. This also includes the component

drivers: base: component: Add debug message for unbind

Like when binding component, add a debug message to the unbinding case
to make it easy to track the lifecycle. This also includes the component
pointer since that is used to open a group in devres, making it easier
to track the resources.

Acked-by: Greg Kroah-Hartman <[email protected]>
Reviewed-by: Rodrigo Vivi <[email protected]>
Reviewed-by: Tejas Upadhyay <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Signed-off-by: Lucas De Marchi <[email protected]>

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drivers: base: component: Allow more space for device name

Some drivers use <BDF>-<UUID> as the aggregate device name which uses
more than 20 chars, causing the status not to be aligned correctly.
E

drivers: base: component: Allow more space for device name

Some drivers use <BDF>-<UUID> as the aggregate device name which uses
more than 20 chars, causing the status not to be aligned correctly.
Example for mei_gsc_proxy on LNL:

Before:
aggregate_device name status
-------------------------------------------------------------
0000:00:16.0-0f73db04-97ab-4125-b893-e904ad0d5464 bound

After:
aggregate_device name status
-----------------------------------------------------------------------
0000:00:16.0-0f73db04-97ab-4125-b893-e904ad0d5464 bound

Give it 10 more chars for proper alignment.

Signed-off-by: Lucas De Marchi <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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driver core: component: fix spellos

Correct spelling mistakes reported by codespell.

Signed-off-by: Randy Dunlap <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: dri-devel@li

driver core: component: fix spellos

Correct spelling mistakes reported by codespell.

Signed-off-by: Randy Dunlap <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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drivers: base: component: fix memory leak with using debugfs_lookup()

When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make thing

drivers: base: component: fix memory leak with using debugfs_lookup()

When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.

Cc: "Rafael J. Wysocki" <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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component: Add common helper for compare/release functions

The component requires the compare/release functions, there are so many
copies in current kernel. Just define four common helpers for them.

component: Add common helper for compare/release functions

The component requires the compare/release functions, there are so many
copies in current kernel. Just define four common helpers for them.

Cc: Greg Kroah-Hartman <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Signed-off-by: Yong Wu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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component: Replace most references to 'master' with 'aggregate device'

Remove most references to 'master' in the code and replace them with
some form of 'aggregate device'. This better reflects the

component: Replace most references to 'master' with 'aggregate device'

Remove most references to 'master' in the code and replace them with
some form of 'aggregate device'. This better reflects the reality of
what this code does, i.e. an aggregate device that represents a
device like a GPU card once some set of devices that make up the
aggregate device probe and register with the component framework.

Cc: Daniel Vetter <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Laurent Pinchart <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Rob Clark <[email protected]>
Cc: Russell King <[email protected]>
Cc: Saravana Kannan <[email protected]>
Signed-off-by: Stephen Boyd <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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component: do not leave master devres group open after bind

In current code, the devres group for aggregate master is left open
after call to component_master_add_*(). This leads to problems when th

component: do not leave master devres group open after bind

In current code, the devres group for aggregate master is left open
after call to component_master_add_*(). This leads to problems when the
master does further managed allocations on its own. When any
participating driver calls component_del(), this leads to immediate
release of resources.

This came up when investigating a page fault occurring with i915 DRM
driver unbind with 5.15-rc1 kernel. The following sequence occurs:

i915_pci_remove()
-> intel_display_driver_unregister()
-> i915_audio_component_cleanup()
-> component_del()
-> component.c:take_down_master()
-> hdac_component_master_unbind() [via master->ops->unbind()]
-> devres_release_group(master->parent, NULL)

With older kernels this has not caused issues, but with audio driver
moving to use managed interfaces for more of its allocations, this no
longer works. Devres log shows following to occur:

component_master_add_with_match()
[ 126.886032] snd_hda_intel 0000:00:1f.3: DEVRES ADD 00000000323ccdc5 devm_component_match_release (24 bytes)
[ 126.886045] snd_hda_intel 0000:00:1f.3: DEVRES ADD 00000000865cdb29 grp< (0 bytes)
[ 126.886049] snd_hda_intel 0000:00:1f.3: DEVRES ADD 000000001b480725 grp< (0 bytes)

audio driver completes its PCI probe()
[ 126.892238] snd_hda_intel 0000:00:1f.3: DEVRES ADD 000000001b480725 pcim_iomap_release (48 bytes)

component_del() called() at DRM/i915 unbind()
[ 137.579422] i915 0000:00:02.0: DEVRES REL 00000000ef44c293 grp< (0 bytes)
[ 137.579445] snd_hda_intel 0000:00:1f.3: DEVRES REL 00000000865cdb29 grp< (0 bytes)
[ 137.579458] snd_hda_intel 0000:00:1f.3: DEVRES REL 000000001b480725 pcim_iomap_release (48 bytes)

So the "devres_release_group(master->parent, NULL)" ends up freeing the
pcim_iomap allocation. Upon next runtime resume, the audio driver will
cause a page fault as the iomap alloc was released without the driver
knowing about it.

Fix this issue by using the "struct master" pointer as identifier for
the devres group, and by closing the devres group after
the master->ops->bind() call is done. This allows devres allocations
done by the driver acting as master to be isolated from the binding state
of the aggregate driver. This modifies the logic originally introduced in
commit 9e1ccb4a7700 ("drivers/base: fix devres handling for master device")

Fixes: 9e1ccb4a7700 ("drivers/base: fix devres handling for master device")
Cc: [email protected]
Acked-by: Imre Deak <[email protected]>
Acked-by: Russell King (Oracle) <[email protected]>
Signed-off-by: Kai Vehmanen <[email protected]>
BugLink: https://gitlab.freedesktop.org/drm/intel/-/issues/4136
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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drivers/base/component.c: remove superfluous header files from component.c

component.c hasn't use any macro or function declared in linux/kref.h.
Thus, these files can be removed from component.c sa

drivers/base/component.c: remove superfluous header files from component.c

component.c hasn't use any macro or function declared in linux/kref.h.
Thus, these files can be removed from component.c safely without
affecting the compilation of the drivers/base/ module

Signed-off-by: Mianhan Liu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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component: Rename 'dev' to 'parent'

Let's rename this struct member to 'parent' to better reflect the
reality that it's the parent device of this psuedo-device. In the next
patch we'll put a 'struct

component: Rename 'dev' to 'parent'

Let's rename this struct member to 'parent' to better reflect the
reality that it's the parent device of this psuedo-device. In the next
patch we'll put a 'struct device' inside of this struct so moving this
away simplifies that patch by reducing the number of places that 'dev'
is modified.

Cc: Daniel Vetter <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Rob Clark <[email protected]>
Cc: Russell King <[email protected]>
Cc: Saravana Kannan <[email protected]>
Signed-off-by: Stephen Boyd <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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component: Drop 'dev' argument to component_match_realloc()

This argument isn't used. Drop it.

Cc: Daniel Vetter <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Rob Clark <

component: Drop 'dev' argument to component_match_realloc()

This argument isn't used. Drop it.

Cc: Daniel Vetter <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Rob Clark <[email protected]>
Cc: Russell King <[email protected]>
Cc: Saravana Kannan <[email protected]>
Signed-off-by: Stephen Boyd <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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driver core: component: remove dentry pointer in "struct master"

There is no need to keep around a pointer to a dentry when all it is
used for is to remove the debugfs file when tearing things down.

driver core: component: remove dentry pointer in "struct master"

There is no need to keep around a pointer to a dentry when all it is
used for is to remove the debugfs file when tearing things down. As the
name is simple, have debugfs look up the dentry when removing things,
keeping the logic much simpler.

Cc: "Rafael J. Wysocki" <[email protected]>
Cc: [email protected]
Reviewed-by: Rafael J. Wysocki <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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component: Silence bind error on -EPROBE_DEFER

If a component fails to bind due to -EPROBE_DEFER we should not log an
error as this is not a real failure.

Fixes messages like:
vc4-drm soc:gpu: fail

component: Silence bind error on -EPROBE_DEFER

If a component fails to bind due to -EPROBE_DEFER we should not log an
error as this is not a real failure.

Fixes messages like:
vc4-drm soc:gpu: failed to bind 3f902000.hdmi (ops vc4_hdmi_ops): -517
vc4-drm soc:gpu: master bind failed: -517

Signed-off-by: James Hilliard <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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component: allow missing unbind callback

The component framework reuses the devres managed functions. There is no
need to specify an unbind() callback if the driver only wants to release
the devres

component: allow missing unbind callback

The component framework reuses the devres managed functions. There is no
need to specify an unbind() callback if the driver only wants to release
the devres managed resources. The bind/unbind is like the probe/remove
pair. The bind/probe is necessary and the unbind/remove is optional.

Signed-off-by: Marco Felsch <[email protected]>
Reviewed-by: Philipp Zabel <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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component: do not dereference opaque pointer in debugfs

The match data does not have to be a struct device pointer, and indeed
very often is not. Attempt to treat it as such easily results in a
cras

component: do not dereference opaque pointer in debugfs

The match data does not have to be a struct device pointer, and indeed
very often is not. Attempt to treat it as such easily results in a
crash.

For the components that are not registered, we don't know which device
is missing. Once it it is there, we can use the struct component to get
the device and whether it's bound or not.

Fixes: 59e73854b5fd ('component: add debugfs support')
Signed-off-by: Lubomir Rintel <[email protected]>
Cc: stable <[email protected]>
Cc: Arnaud Pouliquen <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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drivers/component: remove modular code

drivers/base/Makefile always adds component.o to obj-y, like this:

obj-y := component.o core.o bus.o dd.o syscore.o \

Hence it is never c

drivers/component: remove modular code

drivers/base/Makefile always adds component.o to obj-y, like this:

obj-y := component.o core.o bus.o dd.o syscore.o \

Hence it is never compiled as a module. Remove useless modular code.

Signed-off-by: Masahiro Yamada <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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drivers/component: kerneldoc polish

Polish the kerneldoc a bit with suggestions from Randy.

v2: Randy found another typo: s/compent/component/

Signed-off-by: Daniel Vetter <[email protected]

drivers/component: kerneldoc polish

Polish the kerneldoc a bit with suggestions from Randy.

v2: Randy found another typo: s/compent/component/

Signed-off-by: Daniel Vetter <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: Ramalingam C <[email protected]>
Acked-by: Randy Dunlap <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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components: multiple components for a device

Component framework is extended to support multiple components for
a struct device. These will be matched with different masters based on
its sub compone

components: multiple components for a device

Component framework is extended to support multiple components for
a struct device. These will be matched with different masters based on
its sub component value.

We are introducing this, as I915 needs two different components
with different subcomponent value, which will be matched to two
different component masters(Audio and HDCP) based on the subcomponent
values.

v2: Add documenation.

v3: Rebase on top of updated documenation.

v4: Review from Rafael:
- Remove redundant "This" from kerneldoc (also in the previous patch)
- Streamline the logic in find_component() a bit.

Signed-off-by: Daniel Vetter <[email protected]> (v1 code)
Signed-off-by: Ramalingam C <[email protected]> (v1 commit message)
Cc: Ramalingam C <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Russell King <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: Jaroslav Kysela <[email protected]>
Cc: Takashi Iwai <[email protected]>
Cc: Rodrigo Vivi <[email protected]>
Cc: Jani Nikula <[email protected]>
Reviewed-by: Greg Kroah-Hartman <[email protected]>
Reviewed-by: Rafael J. Wysocki <[email protected]>
Signed-off-by: Daniel Vetter <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

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component: Add documentation

While typing these I think doing an s/component_master/aggregate/
would be useful:
- it's shorter :-)
- I think component/aggregate is much more meaningful naming than

component: Add documentation

While typing these I think doing an s/component_master/aggregate/
would be useful:
- it's shorter :-)
- I think component/aggregate is much more meaningful naming than
component/puppetmaster or something like that. At least to my
English ear "aggregate" emphasizes much more the "assemble a pile of
things into something bigger" aspect, and there's not really much
of a control hierarchy between aggregate and constituing components.

But that's way more than a quick doc typing exercise ...

Thanks to Ram for commenting on an initial draft of these docs.

v2: Review from Rafael:
- git add Documenation/driver-api/component.rst
- lots of polish to the wording + spelling fixes.

v3: Review from Russell:
- s/framework/helper
- clarify the documentation for component_match_add functions.

v4: Remove a few superflous "This".

Reviewed-by: Rafael J. Wysocki <[email protected]>
Cc: "C, Ramalingam" <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Russell King <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: Jaroslav Kysela <[email protected]>
Cc: Takashi Iwai <[email protected]>
Cc: Rodrigo Vivi <[email protected]>
Cc: Jani Nikula <[email protected]>
Reviewed-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Daniel Vetter <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

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component: convert to DEFINE_SHOW_ATTRIBUTE

Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code.

Signed-off-by: Yangtao Li <[email protected]>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfo

component: convert to DEFINE_SHOW_ATTRIBUTE

Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code.

Signed-off-by: Yangtao Li <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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component: fix loop condition to call unbind() if bind() fails

During component_bind_all(), if bind() fails for any
particular component associated with a master, unbind()
should be called for all p

component: fix loop condition to call unbind() if bind() fails

During component_bind_all(), if bind() fails for any
particular component associated with a master, unbind()
should be called for all previous components in that
master's match array, whose bind() might have completed
successfully. As per the current logic, if bind() fails
for the component at position 'n' in the master's match
array, it would start calling unbind() from component in
'n'th position itself and work backwards, and will always
skip calling unbind() for component in 0th position in the
master's match array.
Fix this by updating the loop condition, and the logic to
refer to the components in master's match array, so that
unbind() is called for all components starting from 'n-1'st
position in the array, until (and including) component in
0th position.

Signed-off-by: Banajit Goswami <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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component: add debugfs support

Currently there is no information in any vfs about which devices
a master component consists of, what makes debugging hard if
one of the component devices fails to reg

component: add debugfs support

Currently there is no information in any vfs about which devices
a master component consists of, what makes debugging hard if
one of the component devices fails to register.

Add 'device_component' directory to debugfs. Create a new file for each
component master, when it has been added. Remove it on a master
deletion. Show a list of devices required by the given master and their
status (registered or not). This provides an easy way to check, which
device has failed to register if the given master device is not
available in the system.

Signed-off-by: Maciej Purski <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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driver core: Remove redundant license text

Now that the SPDX tag is in all driver core files, that identifies the
license in a specific and legally-defined manner. So the extra GPL text
wording can

driver core: Remove redundant license text

Now that the SPDX tag is in all driver core files, that identifies the
license in a specific and legally-defined manner. So the extra GPL text
wording can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text. And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Johannes Berg <[email protected]>
Cc: "Luis R. Rodriguez" <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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driver core: add SPDX identifiers to all driver core files

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the driver core fi

driver core: add SPDX identifiers to all driver core files

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the driver core files files with the correct SPDX license
identifier based on the license text in the file itself. The SPDX
identifier is a legally binding shorthand, which can be used instead of
the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Johannes Berg <[email protected]>
Cc: "Luis R. Rodriguez" <[email protected]>
Cc: William Breathitt Gray <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Kate Stewart <[email protected]>
Cc: Philippe Ombredanne <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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component: remove device from master match list on failed add

Calling component_add() may result in the completion of a set of
devices, which will try to bring up a master. In bringing the master
up

component: remove device from master match list on failed add

Calling component_add() may result in the completion of a set of
devices, which will try to bring up a master. In bringing the master
up, we populate its match array with the current set of children.

If binding any of the devices fails, component_add() itself will fail,
free the struct component entry, and return to the caller. The
now-freed entry is never removed from the master's match array, and
will later be used in a futile attempt to bind to freed memory.

Bring component_add's behaviour on failure to bring up a master into
line with component_del by removing the (to-be-freed) component from
the master's match array.

The specific case which broke was:
- rockchip_drm_drv adds a component master
- dwhdmi_rockchip adds a child component in probe (master incomplete)
- rockchip_drm_vop adds two children in probe, which completes the
set
- inside component_add, we try to bring up the master, having
populated the master's match array, and fail with EPROBE_DEFER from
dwhdmi_rockchip; we delete the putative component
- rockchip_drm_vop's probe fails and returns EPROBE_DEFER
- we later re-probe rockchip_drm_vop and add the component; the
master is complete, so we attempt to bring it up again
- walking the match array, we find the previous child, whose master
pointer doesn't match (as it has been freed in the meantime)
- rockchip_drm_vop probe fails, and will never be attempted again

Fixes: ffc30b74fd6d01588bd3fdebc3b1acc0857e6fc8
Signed-off-by: Daniel Stone <[email protected]>
Cc: Russell King <[email protected]>
Cc: Thierry Reding <[email protected]>
Cc: Laurent Pinchart <[email protected]>
Signed-off-by: Russell King <[email protected]>

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