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Message-ID: <6ecd5694-cb60-dda2-5092-cf14920c5877@redhat.com>
Date:   Tue, 30 Aug 2022 16:50:11 +0200
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Subject: Re: [PATCH v3 1/4] ACPI: s2idle: Add a new ->check() callback for
 platform_s2idle_ops
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To:     "Limonciello, Mario" <mario.limonciello@amd.com>,
        "Rafael J. Wysocki" <rafael@kernel.org>
Cc:     Len Brown <lenb@kernel.org>, Pavel Machek <pavel@ucw.cz>,
        ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux PM <linux-pm@vger.kernel.org>,
        Shyam-sundar S-k <Shyam-sundar.S-k@amd.com>
References: <20220829162953.5947-1-mario.limonciello@amd.com>
 <20220829162953.5947-2-mario.limonciello@amd.com>
 <CAJZ5v0iF1_MUptawLL4DD0RqZpysH2B+Pk5sj_=gLv9AOVdy=Q@mail.gmail.com>
 <88b5f4aa-d238-efb6-82fd-e227c42cc10c@amd.com>
From:   Hans de Goede <hdegoede@redhat.com>
In-Reply-To: <88b5f4aa-d238-efb6-82fd-e227c42cc10c@amd.com>
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Hi,

On 8/30/22 13:42, Limonciello, Mario wrote:
> On 8/30/2022 06:39, Rafael J. Wysocki wrote:
>> On Mon, Aug 29, 2022 at 6:29 PM Mario Limonciello
>> <mario.limonciello@amd.com> wrote:
>>>
>>> On some platforms it is found that Linux more aggressively enters s2idle
>>> than Windows enters Modern Standby and this uncovers some synchronization
>>> issues for the platform.  To aid in debugging this class of problems in
>>> the future, add support for an extra optional callback intended for
>>> drivers to emit extra debugging.
>>>
>>> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
>>
>> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>>
>> and I'm assuming that this is for Hans.
> 
> Thanks, and yeah I think it makes more sense for this to go through platform-x86.

Ok, I will review 2-4 and merge the entire series
through platform-x86.

Regards,

Hans


> 
>>
>>> ---
>>> v2->v3:
>>>   * Rename to *check
>>> v1->v2:
>>>   * Add a prototype for `acpi_s2idle_enter`
>>>
>>>   drivers/acpi/sleep.h      |  1 +
>>>   drivers/acpi/x86/s2idle.c | 14 ++++++++++++++
>>>   include/linux/acpi.h      |  1 +
>>>   include/linux/suspend.h   |  1 +
>>>   kernel/power/suspend.c    |  3 +++
>>>   5 files changed, 20 insertions(+)
>>>
>>> diff --git a/drivers/acpi/sleep.h b/drivers/acpi/sleep.h
>>> index 7fe41ee489d6..d960a238be4e 100644
>>> --- a/drivers/acpi/sleep.h
>>> +++ b/drivers/acpi/sleep.h
>>> @@ -18,6 +18,7 @@ static inline acpi_status acpi_set_waking_vector(u32 wakeup_address)
>>>   extern int acpi_s2idle_begin(void);
>>>   extern int acpi_s2idle_prepare(void);
>>>   extern int acpi_s2idle_prepare_late(void);
>>> +extern void acpi_s2idle_check(void);
>>>   extern bool acpi_s2idle_wake(void);
>>>   extern void acpi_s2idle_restore_early(void);
>>>   extern void acpi_s2idle_restore(void);
>>> diff --git a/drivers/acpi/x86/s2idle.c b/drivers/acpi/x86/s2idle.c
>>> index f9ac12b778e6..474aa46f82f6 100644
>>> --- a/drivers/acpi/x86/s2idle.c
>>> +++ b/drivers/acpi/x86/s2idle.c
>>> @@ -486,6 +486,19 @@ int acpi_s2idle_prepare_late(void)
>>>          return 0;
>>>   }
>>>
>>> +void acpi_s2idle_check(void)
>>> +{
>>> +       struct acpi_s2idle_dev_ops *handler;
>>> +
>>> +       if (!lps0_device_handle || sleep_no_lps0)
>>> +               return;
>>> +
>>> +       list_for_each_entry(handler, &lps0_s2idle_devops_head, list_node) {
>>> +               if (handler->check)
>>> +                       handler->check();
>>> +       }
>>> +}
>>> +
>>>   void acpi_s2idle_restore_early(void)
>>>   {
>>>          struct acpi_s2idle_dev_ops *handler;
>>> @@ -527,6 +540,7 @@ static const struct platform_s2idle_ops acpi_s2idle_ops_lps0 = {
>>>          .begin = acpi_s2idle_begin,
>>>          .prepare = acpi_s2idle_prepare,
>>>          .prepare_late = acpi_s2idle_prepare_late,
>>> +       .check = acpi_s2idle_check,
>>>          .wake = acpi_s2idle_wake,
>>>          .restore_early = acpi_s2idle_restore_early,
>>>          .restore = acpi_s2idle_restore,
>>> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
>>> index 6f64b2f3dc54..acaa2ddc067d 100644
>>> --- a/include/linux/acpi.h
>>> +++ b/include/linux/acpi.h
>>> @@ -1075,6 +1075,7 @@ acpi_status acpi_os_prepare_extended_sleep(u8 sleep_state,
>>>   struct acpi_s2idle_dev_ops {
>>>          struct list_head list_node;
>>>          void (*prepare)(void);
>>> +       void (*check)(void);
>>>          void (*restore)(void);
>>>   };
>>>   int acpi_register_lps0_dev(struct acpi_s2idle_dev_ops *arg);
>>> diff --git a/include/linux/suspend.h b/include/linux/suspend.h
>>> index 70f2921e2e70..03ed42ed2c7f 100644
>>> --- a/include/linux/suspend.h
>>> +++ b/include/linux/suspend.h
>>> @@ -191,6 +191,7 @@ struct platform_s2idle_ops {
>>>          int (*begin)(void);
>>>          int (*prepare)(void);
>>>          int (*prepare_late)(void);
>>> +       void (*check)(void);
>>>          bool (*wake)(void);
>>>          void (*restore_early)(void);
>>>          void (*restore)(void);
>>> diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
>>> index 827075944d28..c6272d466e58 100644
>>> --- a/kernel/power/suspend.c
>>> +++ b/kernel/power/suspend.c
>>> @@ -136,6 +136,9 @@ static void s2idle_loop(void)
>>>                          break;
>>>                  }
>>>
>>> +               if (s2idle_ops && s2idle_ops->check)
>>> +                       s2idle_ops->check();
>>> +
>>>                  s2idle_enter();
>>>          }
>>>
>>> -- 
>>> 2.34.1
>>>
>