Re: [net-next RFC PATCH 1/2] net: mdio: implement mdio_mutex_nested guard() variant

[Markus Elfring <Markus.Elfring@web.de>]

> Implement mdio_mutex_nested guard() variant.

I find the idea generally helpful.
The concrete implementation needs further clarifications.


> guard() compes from the cleanup.h API that define handy class to

          comes?                             defines?


> define the lifecycle of a critical section.

  handle?


> Many driver makes use of the mutex_lock_nested()/mutex_unlock() hence it

  Several drivers use?                                            function call pair.

Would you like to clarify any application statistics another bit?
https://elixir.bootlin.com/linux/v6.10-rc5/A/ident/mutex_lock_nested


> might be sensible to provide a variant of the generic guard(mutex),

  Hence it is?                                                      :


> guard(mdio_mutex_nested) to also support drivers that use
> mutex_lock_nested with MDIO_MUTEX_NESTED.

Another wording suggestion:
  guard(mdio_mutex_nested) so that drivers can be better supported
  with the call variant “mutex_lock_nested(…, MDIO_MUTEX_NESTED)”.


…
> +++ b/include/linux/mdio.h
> @@ -8,6 +8,8 @@
>
>  #include <uapi/linux/mdio.h>
>  #include <linux/bitfield.h>
> +#include <linux/cleanup.h>

I suggest to omit this preprocessing directive here.


> +#include <linux/mutex.h>
>  #include <linux/mod_devicetable.h>
…

Further information is included as possibly needed.
https://elixir.bootlin.com/linux/v6.10-rc5/source/include/linux/mutex.h#L22

How reasonable is the added header file dependency so far?


Under which circumstances can remaining change resistance be adjusted
for further benefits from applications of scope-based resource management?

Regards,
Markus