Currently, the driver's device private data is allocated and initialized
from driver core code called from bus abstractions after the driver's
probe() callback returned the corresponding initializer.

Similarly, the driver's device private data is dropped within the
remove() callback of bus abstractions after calling the remove()
callback of the corresponding driver.

However, commit 6f61a2637abe ("rust: device: introduce
Device::drvdata()") introduced an accessor for the driver's device
private data for a Device<Bound>, i.e. a device that is currently bound
to a driver.

Obviously, this is in conflict with dropping the driver's device private
data in remove(), since a device can not be considered to be fully
unbound after remove() has finished:

We also have to consider registrations guarded by devres - such as IRQ
or class device registrations - which are torn down after remove() in
devres_release_all().

Thus, it can happen that, for instance, a class device or IRQ callback
still calls Device::drvdata(), which then runs concurrently to remove()
(which sets dev->driver_data to NULL and drops the driver's device
private data), before devres_release_all() started to tear down the
corresponding registration. This is because devres guarded registrations
can, as expected, access the corresponding Device<Bound> that defines
their scope.

In C it simply is the driver's responsibility to ensure that its device
private data is freed after e.g. an IRQ registration is unregistered.

Typically, C drivers achieve this by allocating their device private data
with e.g. devm_kzalloc() before doing anything else, i.e. before e.g.
registering an IRQ with devm_request_threaded_irq(), relying on the
reverse order cleanup of devres [1].

Technically, we could do something similar in Rust. However, the
resulting code would be pretty messy:

In Rust we have to differentiate between allocated but uninitialized
memory and initialized memory in the type system. Thus, we would need to
somehow keep track of whether the driver's device private data object
has been initialized (i.e. probe() was successful and returned a valid
initializer for this memory) and conditionally call the destructor of
the corresponding object when it is freed.

This is because we'd need to allocate and register the memory of the
driver's device private data *before* it is initialized by the
initializer returned by the driver's probe() callback, because the
driver could already register devres guarded registrations within
probe() outside of the driver's device private data initializer.

Luckily there is a much simpler solution: Instead of dropping the
driver's device private data at the end of remove(), we just drop it
after the device has been fully unbound, i.e. after all devres callbacks
have been processed.

For this, we introduce a new post_unbind() callback private to the
driver-core, i.e. the callback is neither exposed to drivers, nor to bus
abstractions.

This way, the driver-core code can simply continue to conditionally
allocate the memory for the driver's device private data when the
driver's initializer is returned from probe() - no change needed - and
drop it when the driver-core code receives the post_unbind() callback.

--

Dependency wise we need a common Driver trait that describes the layout of a
specific driver structure, such as struct pci_driver or struct platform_driver.
Additional to this specific driver type (which was previously the associated
type RegType of the RegistrationOps) it provides the offset to the embedded
struct device_driver and the type of the driver's device private data.

This patch series contains two additional dependencies:

  (1) A fix for i2c::Driver::shutdown() to not free the driver's device
      private data at all, which otherwise causes the exact same bug, and
      is not necessary in the first place anyways.

  (2) Add the auxiliary::Driver::unbind() callback. Strictly speaking,
      this is not a dependency, but without this patch the main fix of this
      series leaves the remove() callback of the auxiliary bus
      abstraction with either dead code or quite some code removed;
      code that we would otherwise add back immediately afterwards.

--

[1] In fact, the cleanup ordering of devres is a separate challenge in
    Rust, since it is technically unsound to rely on the driver to pick
    the correct order. I am already working on a solution for this;
    luckily this also has some synergies with optimizing the required
    synchronize_rcu() calls required by the Rust Devres container
    structure down to exactly one per driver unbind.

Link: https://git.kernel.org/pub/scm/linux/kernel/git/dakr/linux.git/log/?h=driver/post_unbind

Danilo Krummrich (6):
  rust: i2c: do not drop device private data on shutdown()
  rust: auxiliary: add Driver::unbind() callback
  rust: driver: introduce a common Driver trait
  rust: driver: add DEVICE_DRIVER_OFFSET to the Driver trait
  rust: driver: add DriverData type to the generic Driver trait
  rust: driver: drop device private data post unbind

 drivers/base/dd.c             |  4 ++
 include/linux/device/driver.h | 11 +++++
 rust/kernel/auxiliary.rs      | 41 +++++++++++++----
 rust/kernel/device.rs         | 20 ++++----
 rust/kernel/driver.rs         | 86 ++++++++++++++++++++++++++++-------
 rust/kernel/i2c.rs            | 31 ++++++++-----
 rust/kernel/pci.rs            | 27 +++++++----
 rust/kernel/platform.rs       | 27 +++++++----
 rust/kernel/usb.rs            | 27 +++++++----
 9 files changed, 203 insertions(+), 71 deletions(-)


base-commit: 8510ef5e3cfbd7d59a16845f85cd0194a8689761
-- 
2.52.0

On Wed, Jan 07, 2026 at 11:34:59AM +0100, Danilo Krummrich wrote:
> Currently, the driver's device private data is allocated and initialized
> from driver core code called from bus abstractions after the driver's
> probe() callback returned the corresponding initializer.
> 
> Similarly, the driver's device private data is dropped within the
> remove() callback of bus abstractions after calling the remove()
> callback of the corresponding driver.
> 
> However, commit 6f61a2637abe ("rust: device: introduce
> Device::drvdata()") introduced an accessor for the driver's device
> private data for a Device<Bound>, i.e. a device that is currently bound
> to a driver.
> 
> Obviously, this is in conflict with dropping the driver's device private
> data in remove(), since a device can not be considered to be fully
> unbound after remove() has finished:
> 
> We also have to consider registrations guarded by devres - such as IRQ
> or class device registrations - which are torn down after remove() in
> devres_release_all().
> 
> Thus, it can happen that, for instance, a class device or IRQ callback
> still calls Device::drvdata(), which then runs concurrently to remove()
> (which sets dev->driver_data to NULL and drops the driver's device
> private data), before devres_release_all() started to tear down the
> corresponding registration. This is because devres guarded registrations
> can, as expected, access the corresponding Device<Bound> that defines
> their scope.
> 
> In C it simply is the driver's responsibility to ensure that its device
> private data is freed after e.g. an IRQ registration is unregistered.
> 
> Typically, C drivers achieve this by allocating their device private data
> with e.g. devm_kzalloc() before doing anything else, i.e. before e.g.
> registering an IRQ with devm_request_threaded_irq(), relying on the
> reverse order cleanup of devres [1].
> 
> Technically, we could do something similar in Rust. However, the
> resulting code would be pretty messy:
> 
> In Rust we have to differentiate between allocated but uninitialized
> memory and initialized memory in the type system. Thus, we would need to
> somehow keep track of whether the driver's device private data object
> has been initialized (i.e. probe() was successful and returned a valid
> initializer for this memory) and conditionally call the destructor of
> the corresponding object when it is freed.
> 
> This is because we'd need to allocate and register the memory of the
> driver's device private data *before* it is initialized by the
> initializer returned by the driver's probe() callback, because the
> driver could already register devres guarded registrations within
> probe() outside of the driver's device private data initializer.
> 
> Luckily there is a much simpler solution: Instead of dropping the
> driver's device private data at the end of remove(), we just drop it
> after the device has been fully unbound, i.e. after all devres callbacks
> have been processed.
> 
> For this, we introduce a new post_unbind() callback private to the
> driver-core, i.e. the callback is neither exposed to drivers, nor to bus
> abstractions.
> 
> This way, the driver-core code can simply continue to conditionally
> allocate the memory for the driver's device private data when the
> driver's initializer is returned from probe() - no change needed - and
> drop it when the driver-core code receives the post_unbind() callback.
> 
> --
> 
> Dependency wise we need a common Driver trait that describes the layout of a
> specific driver structure, such as struct pci_driver or struct platform_driver.
> Additional to this specific driver type (which was previously the associated
> type RegType of the RegistrationOps) it provides the offset to the embedded
> struct device_driver and the type of the driver's device private data.
> 
> This patch series contains two additional dependencies:
> 
>   (1) A fix for i2c::Driver::shutdown() to not free the driver's device
>       private data at all, which otherwise causes the exact same bug, and
>       is not necessary in the first place anyways.
> 
>   (2) Add the auxiliary::Driver::unbind() callback. Strictly speaking,
>       this is not a dependency, but without this patch the main fix of this
>       series leaves the remove() callback of the auxiliary bus
>       abstraction with either dead code or quite some code removed;
>       code that we would otherwise add back immediately afterwards.
> 
> --
> 
> [1] In fact, the cleanup ordering of devres is a separate challenge in
>     Rust, since it is technically unsound to rely on the driver to pick
>     the correct order. I am already working on a solution for this;
>     luckily this also has some synergies with optimizing the required
>     synchronize_rcu() calls required by the Rust Devres container
>     structure down to exactly one per driver unbind.

I don't think these are really separate problems. And I think this may
be the wrong fix.

If a &Device<Bound> lets you access a given value, then we must not
destroy that value until after the last &Device<Bound> has expired.

A &Device<Bound> lets you access the driver private data. And a
&Device<Bound> lets you access the contents of a Devres<T>.

Thus, the last &Device<Bound> must expire before we destroy driver
private data or values inside of Devres<T>. Etc.

What are sources of &Device<Bound> today?

* Most driver callbacks.
* IRQ callbacks.
* Workqueue callbacks. (In the future.)
* I think that's it ...?

Thus, we must call free_irq() before we destroy *the first* Devres<T>
resource or the driver private data.

Thus, we must ensure that driver callbacks are somehow synchronized to
exit before we destroy *the first* Devres<T> resource or the driver
private data.

One thing is that this means that using a Devres<_> container and
callback as the mechanism for calling free_irq() is not possible.

I'm thinking that we may need two domains of callbacks:

1. devm_early_*
2. DEVICE IS NOW CONSIDERED UNBOUND - there must no longer be any &Device<Bound> left
3. free driver private data
4. devm_*

And devm_early_*() would be a new set of callbacks where we can run
things such as free_irq(). It would use a separate DevresEarly<_>
container, for which &Device<Bound> does *not* let you peek inside. And
the usual Devres<_> is cleaned up in step 4, where it is legal to peek
inside given a &Device<Bound>.

We could potentially revoke Devres<_> containers during devm_early_*,
but actually destroy their contents in devm_*. This gives you a clean
mechanism to replace the per-Devres<_> synchronize_rcu() calls with a
single one. (By declaring step 2 must last at least one rcu grace
period.)

Not sure whether remove() should run before or after step (2). If it
runs before, then it does not need to be synchronized with other device
callbacks and can free the driver private data. If it runs after (2),
then we can't destroy driver private data in remove().

Alice

On Wed Jan 7, 2026 at 4:51 PM CET, Alice Ryhl wrote:
> If a &Device<Bound> lets you access a given value, then we must not
> destroy that value until after the last &Device<Bound> has expired.
>
> A &Device<Bound> lets you access the driver private data. And a
> &Device<Bound> lets you access the contents of a Devres<T>.
>
> Thus, the last &Device<Bound> must expire before we destroy driver
> private data or values inside of Devres<T>. Etc.

Yes, the last &Device<Bound> must expire before we destroy the device private
data. This is exactly what is achieved by this patch. The device private data is
destroyed after all devres callbacks have been processed, which guarantees that
there can't be any contexts left that provide a &Device<Bound>.

As for the values inside of a Devres<T>, this is exactly what I refer to in my
paragraph above talking about the unsoundness of the devres cleanup ordering in
Rust.

I also mention that I'm already working on a solution and it is in fact pretty
close to the solution you propose below, i.e. a generic mechanism to support
multiple devres domains (which I also see advantages for in C code).

As mentioned, this will also help with getting the required synchronize_rcu()
calls down to exactly one per device unbind.

Technically, we could utilize such a devres domain for dropping the device
private data, but there is no need to have a separate domain just for this, we
already have a distinct place for dropping and freeing the device private data
after the device has been fully unbound, which is much simpler than a separate
devres domain.

Now, you may argue we don't need a separate devres domain, and that we could use
the non-early devres domain. However, this would have the following implication:

In the destructor of the device private data, drivers could still try to use
device resources stored in the device private data through try_access(), which
may or may not succeed depending on whether the corresponding Devres<T>
containers are part of the device private data initializer or whether they have
been allocated separately.

Or in other words it would leave room for drivers to abuse this behavior.

Therefore, the desired order is:

  1. Driver::unbind() (A place for drivers to tear down the device;
     registrations are up - unless explicitly revoked by the driver (this is a
     semantic choice) - and device resources are accessible.)

  2. devm_early_* (Drop all devres guarded registrations.)

  3. No more &Device<Bound> left.

  4. devm_* (Drop all device resources.)

  5. No more device resources left.

  6. Drop and free device private data. (try_access() will never succeed in the
     destructor of the device private data.

- Danilo

On Wed, Jan 07, 2026 at 05:40:20PM +0100, Danilo Krummrich wrote:
> On Wed Jan 7, 2026 at 4:51 PM CET, Alice Ryhl wrote:
> > If a &Device<Bound> lets you access a given value, then we must not
> > destroy that value until after the last &Device<Bound> has expired.
> >
> > A &Device<Bound> lets you access the driver private data. And a
> > &Device<Bound> lets you access the contents of a Devres<T>.
> >
> > Thus, the last &Device<Bound> must expire before we destroy driver
> > private data or values inside of Devres<T>. Etc.
> 
> Yes, the last &Device<Bound> must expire before we destroy the device private
> data. This is exactly what is achieved by this patch. The device private data is
> destroyed after all devres callbacks have been processed, which guarantees that
> there can't be any contexts left that provide a &Device<Bound>.
> 
> As for the values inside of a Devres<T>, this is exactly what I refer to in my
> paragraph above talking about the unsoundness of the devres cleanup ordering in
> Rust.
> 
> I also mention that I'm already working on a solution and it is in fact pretty
> close to the solution you propose below, i.e. a generic mechanism to support
> multiple devres domains (which I also see advantages for in C code).
> 
> As mentioned, this will also help with getting the required synchronize_rcu()
> calls down to exactly one per device unbind.
> 
> Technically, we could utilize such a devres domain for dropping the device
> private data, but there is no need to have a separate domain just for this, we
> already have a distinct place for dropping and freeing the device private data
> after the device has been fully unbound, which is much simpler than a separate
> devres domain.
> 
> Now, you may argue we don't need a separate devres domain, and that we could use
> the non-early devres domain. However, this would have the following implication:
> 
> In the destructor of the device private data, drivers could still try to use
> device resources stored in the device private data through try_access(), which
> may or may not succeed depending on whether the corresponding Devres<T>
> containers are part of the device private data initializer or whether they have
> been allocated separately.
> 
> Or in other words it would leave room for drivers to abuse this behavior.
> 
> Therefore, the desired order is:
> 
>   1. Driver::unbind() (A place for drivers to tear down the device;
>      registrations are up - unless explicitly revoked by the driver (this is a
>      semantic choice) - and device resources are accessible.)
> 
>   2. devm_early_* (Drop all devres guarded registrations.)
> 
>   3. No more &Device<Bound> left.
> 
>   4. devm_* (Drop all device resources.)
> 
>   5. No more device resources left.
> 
>   6. Drop and free device private data. (try_access() will never succeed in the
>      destructor of the device private data.

so your private data is just the first devres resource ;)

Ok. I'm worried that when you fix Devres, you have to undo changes you
made here. But I guess that's not the end of the world (and maybe you
don't have to).

Concept SGTM. I have not yet reviewed patches in details, but

Acked-by: Alice Ryhl <aliceryhl@google.com>

Alice

On Mon Jan 12, 2026 at 4:34 PM CET, Alice Ryhl wrote:
> On Wed, Jan 07, 2026 at 05:40:20PM +0100, Danilo Krummrich wrote:
>> On Wed Jan 7, 2026 at 4:51 PM CET, Alice Ryhl wrote:
>> > If a &Device<Bound> lets you access a given value, then we must not
>> > destroy that value until after the last &Device<Bound> has expired.
>> >
>> > A &Device<Bound> lets you access the driver private data. And a
>> > &Device<Bound> lets you access the contents of a Devres<T>.
>> >
>> > Thus, the last &Device<Bound> must expire before we destroy driver
>> > private data or values inside of Devres<T>. Etc.
>> 
>> Yes, the last &Device<Bound> must expire before we destroy the device private
>> data. This is exactly what is achieved by this patch. The device private data is
>> destroyed after all devres callbacks have been processed, which guarantees that
>> there can't be any contexts left that provide a &Device<Bound>.
>> 
>> As for the values inside of a Devres<T>, this is exactly what I refer to in my
>> paragraph above talking about the unsoundness of the devres cleanup ordering in
>> Rust.
>> 
>> I also mention that I'm already working on a solution and it is in fact pretty
>> close to the solution you propose below, i.e. a generic mechanism to support
>> multiple devres domains (which I also see advantages for in C code).
>> 
>> As mentioned, this will also help with getting the required synchronize_rcu()
>> calls down to exactly one per device unbind.
>> 
>> Technically, we could utilize such a devres domain for dropping the device
>> private data, but there is no need to have a separate domain just for this, we
>> already have a distinct place for dropping and freeing the device private data
>> after the device has been fully unbound, which is much simpler than a separate
>> devres domain.
>> 
>> Now, you may argue we don't need a separate devres domain, and that we could use
>> the non-early devres domain. However, this would have the following implication:
>> 
>> In the destructor of the device private data, drivers could still try to use
>> device resources stored in the device private data through try_access(), which
>> may or may not succeed depending on whether the corresponding Devres<T>
>> containers are part of the device private data initializer or whether they have
>> been allocated separately.
>> 
>> Or in other words it would leave room for drivers to abuse this behavior.
>> 
>> Therefore, the desired order is:
>> 
>>   1. Driver::unbind() (A place for drivers to tear down the device;
>>      registrations are up - unless explicitly revoked by the driver (this is a
>>      semantic choice) - and device resources are accessible.)
>> 
>>   2. devm_early_* (Drop all devres guarded registrations.)
>> 
>>   3. No more &Device<Bound> left.
>> 
>>   4. devm_* (Drop all device resources.)
>> 
>>   5. No more device resources left.
>> 
>>   6. Drop and free device private data. (try_access() will never succeed in the
>>      destructor of the device private data.
>
> so your private data is just the first devres resource ;)

Correct, that would work as well. However, I have a paragraph in the cover
letter explaining why this implementation is not desirable, i.e. more error
prone implementation and more explicit handling required by bus code.

> Ok. I'm worried that when you fix Devres, you have to undo changes you
> made here. But I guess that's not the end of the world (and maybe you
> don't have to).

For the reasons above this will remain as is even with the Devres rework. With a
separate devres stage it would become less error prone and we could also avoid
bus code involvement, but it would still be more complicated than a simple
callback.

> Concept SGTM. I have not yet reviewed patches in details, but
>
> Acked-by: Alice Ryhl <aliceryhl@google.com>

Thanks for taking a look! :)

On 1/7/2026 10:34 AM, Danilo Krummrich wrote:
> Currently, the driver's device private data is allocated and initialized
> from driver core code called from bus abstractions after the driver's
> probe() callback returned the corresponding initializer.
> 
> Similarly, the driver's device private data is dropped within the
> remove() callback of bus abstractions after calling the remove()
> callback of the corresponding driver.
> 
> However, commit 6f61a2637abe ("rust: device: introduce
> Device::drvdata()") introduced an accessor for the driver's device
> private data for a Device<Bound>, i.e. a device that is currently bound
> to a driver.
> 
> Obviously, this is in conflict with dropping the driver's device private
> data in remove(), since a device can not be considered to be fully
> unbound after remove() has finished:
> 
> We also have to consider registrations guarded by devres - such as IRQ
> or class device registrations - which are torn down after remove() in
> devres_release_all().
> 
> Thus, it can happen that, for instance, a class device or IRQ callback
> still calls Device::drvdata(), which then runs concurrently to remove()
> (which sets dev->driver_data to NULL and drops the driver's device
> private data), before devres_release_all() started to tear down the
> corresponding registration. This is because devres guarded registrations
> can, as expected, access the corresponding Device<Bound> that defines
> their scope.
> 
> In C it simply is the driver's responsibility to ensure that its device
> private data is freed after e.g. an IRQ registration is unregistered.
> 
> Typically, C drivers achieve this by allocating their device private data
> with e.g. devm_kzalloc() before doing anything else, i.e. before e.g.
> registering an IRQ with devm_request_threaded_irq(), relying on the
> reverse order cleanup of devres [1].
> 
> Technically, we could do something similar in Rust. However, the
> resulting code would be pretty messy:
> 
> In Rust we have to differentiate between allocated but uninitialized
> memory and initialized memory in the type system. Thus, we would need to
> somehow keep track of whether the driver's device private data object
> has been initialized (i.e. probe() was successful and returned a valid
> initializer for this memory) and conditionally call the destructor of
> the corresponding object when it is freed.
> 
> This is because we'd need to allocate and register the memory of the
> driver's device private data *before* it is initialized by the
> initializer returned by the driver's probe() callback, because the
> driver could already register devres guarded registrations within
> probe() outside of the driver's device private data initializer.
> 
> Luckily there is a much simpler solution: Instead of dropping the
> driver's device private data at the end of remove(), we just drop it
> after the device has been fully unbound, i.e. after all devres callbacks
> have been processed.
> 
> For this, we introduce a new post_unbind() callback private to the
> driver-core, i.e. the callback is neither exposed to drivers, nor to bus
> abstractions.
> 
> This way, the driver-core code can simply continue to conditionally
> allocate the memory for the driver's device private data when the
> driver's initializer is returned from probe() - no change needed - and
> drop it when the driver-core code receives the post_unbind() callback.
> 
> --
> 
> Dependency wise we need a common Driver trait that describes the layout of a
> specific driver structure, such as struct pci_driver or struct platform_driver.
> Additional to this specific driver type (which was previously the associated
> type RegType of the RegistrationOps) it provides the offset to the embedded
> struct device_driver and the type of the driver's device private data.
> 
> This patch series contains two additional dependencies:
> 
>    (1) A fix for i2c::Driver::shutdown() to not free the driver's device
>        private data at all, which otherwise causes the exact same bug, and
>        is not necessary in the first place anyways.
> 
>    (2) Add the auxiliary::Driver::unbind() callback. Strictly speaking,
>        this is not a dependency, but without this patch the main fix of this
>        series leaves the remove() callback of the auxiliary bus
>        abstraction with either dead code or quite some code removed;
>        code that we would otherwise add back immediately afterwards.
> 
> --
> 
> [1] In fact, the cleanup ordering of devres is a separate challenge in
>      Rust, since it is technically unsound to rely on the driver to pick
>      the correct order. I am already working on a solution for this;
>      luckily this also has some synergies with optimizing the required
>      synchronize_rcu() calls required by the Rust Devres container
>      structure down to exactly one per driver unbind.
> 
> Link: https://git.kernel.org/pub/scm/linux/kernel/git/dakr/linux.git/log/?h=driver/post_unbind
> 
> Danilo Krummrich (6):
>    rust: i2c: do not drop device private data on shutdown()
>    rust: auxiliary: add Driver::unbind() callback
>    rust: driver: introduce a common Driver trait
>    rust: driver: add DEVICE_DRIVER_OFFSET to the Driver trait
>    rust: driver: add DriverData type to the generic Driver trait
>    rust: driver: drop device private data post unbind
> 
>   drivers/base/dd.c             |  4 ++
>   include/linux/device/driver.h | 11 +++++
>   rust/kernel/auxiliary.rs      | 41 +++++++++++++----
>   rust/kernel/device.rs         | 20 ++++----
>   rust/kernel/driver.rs         | 86 ++++++++++++++++++++++++++++-------
>   rust/kernel/i2c.rs            | 31 ++++++++-----
>   rust/kernel/pci.rs            | 27 +++++++----
>   rust/kernel/platform.rs       | 27 +++++++----
>   rust/kernel/usb.rs            | 27 +++++++----
>   9 files changed, 203 insertions(+), 71 deletions(-)
> 
> 
> base-commit: 8510ef5e3cfbd7d59a16845f85cd0194a8689761

For the I2C parts: Acked-by: Igor Korotin <igor.korotin.linux@gmail.com>

Thanks
Igor

On Wed Jan 7, 2026 at 11:34 AM CET, Danilo Krummrich wrote:
> Danilo Krummrich (6):
>   rust: i2c: do not drop device private data on shutdown()
>   rust: auxiliary: add Driver::unbind() callback
>   rust: driver: introduce a common Driver trait

    [ Rename driver::Driver to driver::DriverLayout, as it represents the
      layout of a driver structure rather than the driver structure itself.
      - Danilo ]

>   rust: driver: add DEVICE_DRIVER_OFFSET to the Driver trait
>   rust: driver: add DriverData type to the generic Driver trait
>   rust: driver: drop device private data post unbind

    [ Remove #ifdef CONFIG_RUST, rename post_unbind() to post_unbind_rust().
     - Danilo]

Applied to driver-core-linus, thanks!