[PATCH v5] kernel.h: add comments for enum system_states

[PATCH v5] kernel.h: add comments for enum system_states

[Randy Dunlap]

Provide some basic comments about the system_states and what they imply.
Also convert the comments to kernel-doc format.

Split the enum declaration from the definition of the system_state
variable so that kernel-doc notation works cleanly with it.
This is picked up by Documentation/driver-api/basics.rst so it
does not need further inclusion in the kernel docbooks.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Rafael J. Wysocki <rafael@kernel.org> # v1
---
v2: add Rafael's Ack.
v3: add Andrew
v4: add DOC: so that this DOC: block can be used in Documentation/
    add Greg K-H
    add Jon Corbet, Mauro Chehab, & linux-doc
v5: split enum declaration and definition (Jani Nikula)
    drop the DOC: block since it is no longer needed

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Len Brown <len.brown@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: linux-doc@vger.kernel.org
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
---
 include/linux/kernel.h |   21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

--- linux-next-20250819.orig/include/linux/kernel.h
+++ linux-next-20250819/include/linux/kernel.h
@@ -164,11 +164,23 @@ extern int root_mountflags;
 
 extern bool early_boot_irqs_disabled;
 
-/*
- * Values used for system_state. Ordering of the states must not be changed
+/**
+ * enum system_states - Values used for system_state.
+ *
+ * * @SYSTEM_BOOTING:	%0, no init needed
+ * * @SYSTEM_SCHEDULING: system is ready for scheduling; OK to use RCU
+ * * @SYSTEM_FREEING_INITMEM: system is freeing all of initmem; almost running
+ * * @SYSTEM_RUNNING:	system is up and running
+ * * @SYSTEM_HALT:	system entered clean system halt state
+ * * @SYSTEM_POWER_OFF:	system entered shutdown/clean power off state
+ * * @SYSTEM_RESTART:	system entered emergency power off or normal restart
+ * * @SYSTEM_SUSPEND:	system entered suspend or hibernate state
+ *
+ * Note:
+ * Ordering of the states must not be changed
  * as code checks for <, <=, >, >= STATE.
  */
-extern enum system_states {
+enum system_states {
 	SYSTEM_BOOTING,
 	SYSTEM_SCHEDULING,
 	SYSTEM_FREEING_INITMEM,
@@ -177,7 +189,8 @@ extern enum system_states {
 	SYSTEM_POWER_OFF,
 	SYSTEM_RESTART,
 	SYSTEM_SUSPEND,
-} system_state;
+};
+extern enum system_states system_state;
 
 /*
  * General tracing related utility functions - trace_printk(),

Re: [PATCH v5] kernel.h: add comments for enum system_states

[Mauro Carvalho Chehab]

Em Fri,  5 Sep 2025 22:27:58 -0700
Randy Dunlap <rdunlap@infradead.org> escreveu:

> Provide some basic comments about the system_states and what they imply.
> Also convert the comments to kernel-doc format.
> 
> Split the enum declaration from the definition of the system_state
> variable so that kernel-doc notation works cleanly with it.
> This is picked up by Documentation/driver-api/basics.rst so it
> does not need further inclusion in the kernel docbooks.
> 
> Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
> Acked-by: Rafael J. Wysocki <rafael@kernel.org> # v1
> ---
> v2: add Rafael's Ack.
> v3: add Andrew
> v4: add DOC: so that this DOC: block can be used in Documentation/
>     add Greg K-H
>     add Jon Corbet, Mauro Chehab, & linux-doc
> v5: split enum declaration and definition (Jani Nikula)
>     drop the DOC: block since it is no longer needed
> 
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> Cc: Pavel Machek <pavel@ucw.cz>
> Cc: Len Brown <len.brown@intel.com>
> Cc: linux-pm@vger.kernel.org
> Cc: Jonathan Corbet <corbet@lwn.net>
> Cc: Jani Nikula <jani.nikula@linux.intel.com>
> Cc: linux-doc@vger.kernel.org
> Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
> ---
>  include/linux/kernel.h |   21 +++++++++++++++++----
>  1 file changed, 17 insertions(+), 4 deletions(-)
> 
> --- linux-next-20250819.orig/include/linux/kernel.h
> +++ linux-next-20250819/include/linux/kernel.h
> @@ -164,11 +164,23 @@ extern int root_mountflags;
>  
>  extern bool early_boot_irqs_disabled;
>  
> -/*
> - * Values used for system_state. Ordering of the states must not be changed
> +/**
> + * enum system_states - Values used for system_state.
> + *

> + * * @SYSTEM_BOOTING:	%0, no init needed
> + * * @SYSTEM_SCHEDULING: system is ready for scheduling; OK to use RCU
> + * * @SYSTEM_FREEING_INITMEM: system is freeing all of initmem; almost running
> + * * @SYSTEM_RUNNING:	system is up and running
> + * * @SYSTEM_HALT:	system entered clean system halt state
> + * * @SYSTEM_POWER_OFF:	system entered shutdown/clean power off state
> + * * @SYSTEM_RESTART:	system entered emergency power off or normal restart
> + * * @SYSTEM_SUSPEND:	system entered suspend or hibernate state

You forgot to drop the extra asterisk at the above. definitions.

Fixing it, feel free to add:

Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

> + *
> + * Note:
> + * Ordering of the states must not be changed
>   * as code checks for <, <=, >, >= STATE.
>   */
> -extern enum system_states {
> +enum system_states {
>  	SYSTEM_BOOTING,
>  	SYSTEM_SCHEDULING,
>  	SYSTEM_FREEING_INITMEM,
> @@ -177,7 +189,8 @@ extern enum system_states {
>  	SYSTEM_POWER_OFF,
>  	SYSTEM_RESTART,
>  	SYSTEM_SUSPEND,
> -} system_state;
> +};
> +extern enum system_states system_state;
>  
>  /*
>   * General tracing related utility functions - trace_printk(),



Thanks,
Mauro

Re: [PATCH v5] kernel.h: add comments for enum system_states

[Randy Dunlap]

On 9/6/25 1:58 AM, Mauro Carvalho Chehab wrote:
> Em Fri,  5 Sep 2025 22:27:58 -0700
> Randy Dunlap <rdunlap@infradead.org> escreveu:
> 
>> Provide some basic comments about the system_states and what they imply.
>> Also convert the comments to kernel-doc format.
>>
>> Split the enum declaration from the definition of the system_state
>> variable so that kernel-doc notation works cleanly with it.
>> This is picked up by Documentation/driver-api/basics.rst so it
>> does not need further inclusion in the kernel docbooks.
>>
>> Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
>> Acked-by: Rafael J. Wysocki <rafael@kernel.org> # v1
>> ---
>> v2: add Rafael's Ack.
>> v3: add Andrew
>> v4: add DOC: so that this DOC: block can be used in Documentation/
>>     add Greg K-H
>>     add Jon Corbet, Mauro Chehab, & linux-doc
>> v5: split enum declaration and definition (Jani Nikula)
>>     drop the DOC: block since it is no longer needed
>>
>> Cc: Andrew Morton <akpm@linux-foundation.org>
>> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
>> Cc: Pavel Machek <pavel@ucw.cz>
>> Cc: Len Brown <len.brown@intel.com>
>> Cc: linux-pm@vger.kernel.org
>> Cc: Jonathan Corbet <corbet@lwn.net>
>> Cc: Jani Nikula <jani.nikula@linux.intel.com>
>> Cc: linux-doc@vger.kernel.org
>> Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
>> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
>> ---
>>  include/linux/kernel.h |   21 +++++++++++++++++----
>>  1 file changed, 17 insertions(+), 4 deletions(-)
>>
>> --- linux-next-20250819.orig/include/linux/kernel.h
>> +++ linux-next-20250819/include/linux/kernel.h
>> @@ -164,11 +164,23 @@ extern int root_mountflags;
>>  
>>  extern bool early_boot_irqs_disabled;
>>  
>> -/*
>> - * Values used for system_state. Ordering of the states must not be changed
>> +/**
>> + * enum system_states - Values used for system_state.
>> + *
> 
>> + * * @SYSTEM_BOOTING:	%0, no init needed
>> + * * @SYSTEM_SCHEDULING: system is ready for scheduling; OK to use RCU
>> + * * @SYSTEM_FREEING_INITMEM: system is freeing all of initmem; almost running
>> + * * @SYSTEM_RUNNING:	system is up and running
>> + * * @SYSTEM_HALT:	system entered clean system halt state
>> + * * @SYSTEM_POWER_OFF:	system entered shutdown/clean power off state
>> + * * @SYSTEM_RESTART:	system entered emergency power off or normal restart
>> + * * @SYSTEM_SUSPEND:	system entered suspend or hibernate state
> 
> You forgot to drop the extra asterisk at the above. definitions.

Oops, thanks for catching that. Will fix.

-- 
~Randy