Re: [PATCH] Revert "include/linux/suspend.h: Only show pm_pr_dbg messages at suspend/resume"

[Mario Limonciello <mario.limonciello@amd.com>]

On 4/22/2024 09:45, Rafael J. Wysocki wrote:
> On Mon, Apr 22, 2024 at 4:33 PM Mario Limonciello
> <mario.limonciello@amd.com> wrote:
>>
>> On 4/22/2024 04:36, xiongxin wrote:
>>> This reverts commit cdb8c100d8a4b4e31c829724e40b4fdf32977cce.
>>>
>>> In the suspend process, pm_pr_dbg() is called before setting
>>> pm_suspend_target_state. As a result, this part of the log cannot be
>>> output.
>>>
>>> pm_pr_dbg() also outputs debug logs for hibernate, but
>>> pm_suspend_target_state is not set, resulting in hibernate debug logs
>>> can only be output through dynamic debug, which is very inconvenient.
>>
>> As an alternative, how about exporting and renaming the variable
>> in_suspend in kernel/power/hibernate.c and considering that to tell if
>> the hibernate process is going on?
>>
>> Then it should work just the same as it does at suspend.
> 
> Well, this is not the only part that stopped working AFAICS.  I'll
> queue up the revert.

I just tested the revert to see what happens to other drivers but it's 
going to have more collateral damage.

ERROR: modpost: "pm_debug_messages_on" 
[drivers/platform/x86/amd/pmc/amd-pmc.ko] undefined!

> 
> Thanks!
> 
>>>
>>> Signed-off-by: xiongxin <xiongxin@kylinos.cn>
>>>
>>> diff --git a/include/linux/suspend.h b/include/linux/suspend.h
>>> index da6ebca3ff77..415483b89b11 100644
>>> --- a/include/linux/suspend.h
>>> +++ b/include/linux/suspend.h
>>> @@ -503,7 +503,6 @@ static inline void unlock_system_sleep(unsigned int flags) {}
>>>    #ifdef CONFIG_PM_SLEEP_DEBUG
>>>    extern bool pm_print_times_enabled;
>>>    extern bool pm_debug_messages_on;
>>> -extern bool pm_debug_messages_should_print(void);
>>>    static inline int pm_dyn_debug_messages_on(void)
>>>    {
>>>    #ifdef CONFIG_DYNAMIC_DEBUG
>>> @@ -517,14 +516,14 @@ static inline int pm_dyn_debug_messages_on(void)
>>>    #endif
>>>    #define __pm_pr_dbg(fmt, ...)                                       \
>>>        do {                                                    \
>>> -             if (pm_debug_messages_should_print())           \
>>> +             if (pm_debug_messages_on)                       \
>>>                        printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__);  \
>>>                else if (pm_dyn_debug_messages_on())            \
>>>                        pr_debug(fmt, ##__VA_ARGS__);   \
>>>        } while (0)
>>>    #define __pm_deferred_pr_dbg(fmt, ...)                              \
>>>        do {                                                    \
>>> -             if (pm_debug_messages_should_print())           \
>>> +             if (pm_debug_messages_on)                       \
>>>                        printk_deferred(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); \
>>>        } while (0)
>>>    #else
>>> @@ -542,8 +541,7 @@ static inline int pm_dyn_debug_messages_on(void)
>>>    /**
>>>     * pm_pr_dbg - print pm sleep debug messages
>>>     *
>>> - * If pm_debug_messages_on is enabled and the system is entering/leaving
>>> - *      suspend, print message.
>>> + * If pm_debug_messages_on is enabled, print message.
>>>     * If pm_debug_messages_on is disabled and CONFIG_DYNAMIC_DEBUG is enabled,
>>>     *  print message only from instances explicitly enabled on dynamic debug's
>>>     *  control.
>>> diff --git a/kernel/power/main.c b/kernel/power/main.c
>>> index a9e0693aaf69..aa754241aaa6 100644
>>> --- a/kernel/power/main.c
>>> +++ b/kernel/power/main.c
>>> @@ -611,12 +611,6 @@ power_attr_ro(pm_wakeup_irq);
>>>
>>>    bool pm_debug_messages_on __read_mostly;
>>>
>>> -bool pm_debug_messages_should_print(void)
>>> -{
>>> -     return pm_debug_messages_on && pm_suspend_target_state != PM_SUSPEND_ON;
>>> -}
>>> -EXPORT_SYMBOL_GPL(pm_debug_messages_should_print);
>>> -
>>>    static ssize_t pm_debug_messages_show(struct kobject *kobj,
>>>                                      struct kobj_attribute *attr, char *buf)
>>>    {
>>