This is a feature I found useful to have while writing Nova driver code
that accessed registers alongside other operations. I would find myself
quite confused about whether the guard was held or dropped at a given
point of the code, and it felt like walking through a minefield; this
pattern makes things safer and easier to read according to my experience
writing nova-core code.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
Changes in v4:
- Collected Reviewed-by tags.
- Link to v3: https://lore.kernel.org/r/20250406-try_with-v3-0-c0947842e768@nvidia.com

Changes in v3:
- Add Acked-by from v2.

Changes in v2:
- Use FnOnce for the callback type.
- Rename to try_access_with.
- Don't assume that users will want to map failure to ENXIO and return
  an option.
- Use a single method and let users adapt the behavior using their own
  wrappers/macros.

---
Alexandre Courbot (2):
      rust/revocable: add try_access_with() convenience method
      samples: rust: convert PCI rust sample driver to use try_access_with()

 rust/kernel/revocable.rs        | 16 ++++++++++++++++
 samples/rust/rust_driver_pci.rs | 11 +++++------
 2 files changed, 21 insertions(+), 6 deletions(-)
---
base-commit: 0af2f6be1b4281385b618cb86ad946eded089ac8
change-id: 20250313-try_with-cc9f91dd3b60

Best regards,
-- 
Alexandre Courbot <acourbot@nvidia.com>

On Fri, Apr 11, 2025 at 09:09:37PM +0900, Alexandre Courbot wrote:
> This is a feature I found useful to have while writing Nova driver code
> that accessed registers alongside other operations. I would find myself
> quite confused about whether the guard was held or dropped at a given
> point of the code, and it felt like walking through a minefield; this
> pattern makes things safer and easier to read according to my experience
> writing nova-core code.
> 
> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>

With the following changes, applied to nova-next, thanks!

  * link `None`, `Some`, `Option` in doc-comment

- Danilo

On Fri, Apr 11, 2025 at 09:09:37PM +0900, Alexandre Courbot wrote:
> This is a feature I found useful to have while writing Nova driver code
> that accessed registers alongside other operations. I would find myself
> quite confused about whether the guard was held or dropped at a given
> point of the code, and it felt like walking through a minefield; this
> pattern makes things safer and easier to read according to my experience
> writing nova-core code.

Any concerns taking this through the nova tree?

On 4/11/25 3:15 PM, Danilo Krummrich wrote:
> On Fri, Apr 11, 2025 at 09:09:37PM +0900, Alexandre Courbot wrote:
>> This is a feature I found useful to have while writing Nova driver code
>> that accessed registers alongside other operations. I would find myself
>> quite confused about whether the guard was held or dropped at a given
>> point of the code, and it felt like walking through a minefield; this
>> pattern makes things safer and easier to read according to my experience
>> writing nova-core code.
> 
> Any concerns taking this through the nova tree?

@Miguel: Can I get an ACK for taking it through the nova tree?

On Tue, Apr 22, 2025 at 10:01 AM Danilo Krummrich <dakr@kernel.org> wrote:
>
> @Miguel: Can I get an ACK for taking it through the nova tree?

Sure, please go ahead:

Acked-by: Miguel Ojeda <ojeda@kernel.org>

(Sorry, I missed replying to the other one)

Cheers,
Miguel