Re: [PATCH] ACPI / LPSS: Avoid PM quirks on suspend and resume from S3

[Kai-Heng Feng]

> On 2018Jul26, at 16:14, Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote:
> 
> On Thu, Jul 26, 2018 at 5:46 AM, Kai-Heng Feng
> <kai.heng.feng@xxxxxxxxxxxxx> wrote:
>> Hi Rafael,
>> 
>>> On 2018Jul24, at 18:36, Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> wrote:
>>> 
>>> On Tuesday, July 24, 2018 11:13:42 AM CEST Rafael J. Wysocki wrote:
>>>> On Tuesday, July 24, 2018 10:46:09 AM CEST Kai Heng Feng wrote:
>>>>> Hi Rafael,
>>>>> 
>>>>>> On Jun 13, 2018, at 7:17 PM, Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> wrote:
>>>>>> 
>>>>>> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>>>>>> 
>>>>>> It is reported that commit a192aa923b66a (ACPI / LPSS: Consolidate
>>>>>> runtime PM and system sleep handling) introduced a system suspend
>>>>>> regression on some machines, but the only functional change made by
>>>>>> it was to cause the PM quirks in the LPSS to also be used during
>>>>>> system suspend and resume.  While that should always work for
>>>>>> suspend-to-idle, it turns out to be problematic for S3
>>>>>> (suspend-to-RAM).
>>>>>> 
>>>>>> To address that issue restore the previous S3 suspend and resume
>>>>>> behavior of the LPSS to avoid applying PM quirks then.
>>>>> 
>>>>> The users reported that this patch does fix the S3 issue, but the S4 still
>>>>> fails.
>>>>> 
>>>>> Please refer to [1] for more for user's testing result.
>>>>> 
>>>>> [1] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1774950/comments/60
>>>> 
>>>> Please ask the users to test the patch below, then, on top of the $subject one.
>>> 
>>> There was a mistake in the previous patch I posted, sorry about that.
>>> 
>>> Please test this one instead:
>> 
>> The result is positive, thanks!
> 
> Good, thanks!
> 
> I assume that S3 still works with this patch applied too.

Yes, S3 continues to work with this patch.

Kai-Heng

> 
>>> ---
>>> drivers/acpi/acpi_lpss.c |   26 +++++++++++++++++---------
>>> 1 file changed, 17 insertions(+), 9 deletions(-)
>>> 
>>> Index: linux-pm/drivers/acpi/acpi_lpss.c
>>> ===================================================================
>>> --- linux-pm.orig/drivers/acpi/acpi_lpss.c
>>> +++ linux-pm/drivers/acpi/acpi_lpss.c
>>> @@ -879,6 +879,7 @@ static void acpi_lpss_dismiss(struct dev
>>> #define LPSS_GPIODEF0_DMA_LLP         BIT(13)
>>> 
>>> static DEFINE_MUTEX(lpss_iosf_mutex);
>>> +static bool lpss_iosf_d3_entered;
>>> 
>>> static void lpss_iosf_enter_d3_state(void)
>>> {
>>> @@ -921,6 +922,9 @@ static void lpss_iosf_enter_d3_state(voi
>>> 
>>>      iosf_mbi_modify(LPSS_IOSF_UNIT_LPIOEP, MBI_CR_WRITE,
>>>                      LPSS_IOSF_GPIODEF0, value1, mask1);
>>> +
>>> +     lpss_iosf_d3_entered = true;
>>> +
>>> exit:
>>>      mutex_unlock(&lpss_iosf_mutex);
>>> }
>>> @@ -935,6 +939,11 @@ static void lpss_iosf_exit_d3_state(void
>>> 
>>>      mutex_lock(&lpss_iosf_mutex);
>>> 
>>> +     if (!lpss_iosf_d3_entered)
>>> +             goto exit;
>>> +
>>> +     lpss_iosf_d3_entered = false;
>>> +
>>>      iosf_mbi_modify(LPSS_IOSF_UNIT_LPIOEP, MBI_CR_WRITE,
>>>                      LPSS_IOSF_GPIODEF0, value1, mask1);
>>> 
>>> @@ -944,13 +953,13 @@ static void lpss_iosf_exit_d3_state(void
>>>      iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO1, MBI_CFG_WRITE,
>>>                      LPSS_IOSF_PMCSR, value2, mask2);
>>> 
>>> +exit:
>>>      mutex_unlock(&lpss_iosf_mutex);
>>> }
>>> 
>>> -static int acpi_lpss_suspend(struct device *dev, bool runtime)
>>> +static int acpi_lpss_suspend(struct device *dev, bool wakeup)
>>> {
>>>      struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
>>> -     bool wakeup = runtime || device_may_wakeup(dev);
>>>      int ret;
>>> 
>>>      if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
>>> @@ -963,14 +972,14 @@ static int acpi_lpss_suspend(struct devi
>>>       * wrong status for devices being about to be powered off. See
>>>       * lpss_iosf_enter_d3_state() for further information.
>>>       */
>>> -     if ((runtime || !pm_suspend_via_firmware()) &&
>>> +     if (acpi_target_system_state() == ACPI_STATE_S0 &&
>>>          lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available())
>>>              lpss_iosf_enter_d3_state();
>>> 
>>>      return ret;
>>> }
>>> 
>>> -static int acpi_lpss_resume(struct device *dev, bool runtime)
>>> +static int acpi_lpss_resume(struct device *dev)
>>> {
>>>      struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
>>>      int ret;
>>> @@ -979,8 +988,7 @@ static int acpi_lpss_resume(struct devic
>>>       * This call is kept first to be in symmetry with
>>>       * acpi_lpss_runtime_suspend() one.
>>>       */
>>> -     if ((runtime || !pm_resume_via_firmware()) &&
>>> -         lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available())
>>> +     if (lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available())
>>>              lpss_iosf_exit_d3_state();
>>> 
>>>      ret = acpi_dev_resume(dev);
>>> @@ -1004,12 +1012,12 @@ static int acpi_lpss_suspend_late(struct
>>>              return 0;
>>> 
>>>      ret = pm_generic_suspend_late(dev);
>>> -     return ret ? ret : acpi_lpss_suspend(dev, false);
>>> +     return ret ? ret : acpi_lpss_suspend(dev, device_may_wakeup(dev));
>>> }
>>> 
>>> static int acpi_lpss_resume_early(struct device *dev)
>>> {
>>> -     int ret = acpi_lpss_resume(dev, false);
>>> +     int ret = acpi_lpss_resume(dev);
>>> 
>>>      return ret ? ret : pm_generic_resume_early(dev);
>>> }
>>> @@ -1024,7 +1032,7 @@ static int acpi_lpss_runtime_suspend(str
>>> 
>>> static int acpi_lpss_runtime_resume(struct device *dev)
>>> {
>>> -     int ret = acpi_lpss_resume(dev, true);
>>> +     int ret = acpi_lpss_resume(dev);
>>> 
>>>      return ret ? ret : pm_generic_runtime_resume(dev);
>>> }