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

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

On Wed, 2018-06-13 at 13:17 +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> 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.
> 

LGTM,
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

> Fixes: a192aa923b66a (ACPI / LPSS: Consolidate runtime PM and system
> sleep handling)
> Link: https://bugs.launchpad.net/bugs/1774950
> Reported-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
>  drivers/acpi/acpi_lpss.c |   18 +++++++++++-------
>  1 file changed, 11 insertions(+), 7 deletions(-)
> 
> Index: linux-pm/drivers/acpi/acpi_lpss.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/acpi_lpss.c
> +++ linux-pm/drivers/acpi/acpi_lpss.c
> @@ -22,6 +22,7 @@
>  #include <linux/pm_domain.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/pwm.h>
> +#include <linux/suspend.h>
>  #include <linux/delay.h>
>  
>  #include "internal.h"
> @@ -940,9 +941,10 @@ static void lpss_iosf_exit_d3_state(void
>  	mutex_unlock(&lpss_iosf_mutex);
>  }
>  
> -static int acpi_lpss_suspend(struct device *dev, bool wakeup)
> +static int acpi_lpss_suspend(struct device *dev, bool runtime)
>  {
>  	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)
> @@ -955,13 +957,14 @@ 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 (lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON &&
> iosf_mbi_available())
> +	if ((runtime || !pm_suspend_via_firmware()) &&
> +	    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)
> +static int acpi_lpss_resume(struct device *dev, bool runtime)
>  {
>  	struct lpss_private_data *pdata =
> acpi_driver_data(ACPI_COMPANION(dev));
>  	int ret;
> @@ -970,7 +973,8 @@ static int acpi_lpss_resume(struct devic
>  	 * This call is kept first to be in symmetry with
>  	 * acpi_lpss_runtime_suspend() one.
>  	 */
> -	if (lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON &&
> iosf_mbi_available())
> +	if ((runtime || !pm_resume_via_firmware()) &&
> +	    lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON &&
> iosf_mbi_available())
>  		lpss_iosf_exit_d3_state();
>  
>  	ret = acpi_dev_resume(dev);
> @@ -994,12 +998,12 @@ static int acpi_lpss_suspend_late(struct
>  		return 0;
>  
>  	ret = pm_generic_suspend_late(dev);
> -	return ret ? ret : acpi_lpss_suspend(dev,
> device_may_wakeup(dev));
> +	return ret ? ret : acpi_lpss_suspend(dev, false);
>  }
>  
>  static int acpi_lpss_resume_early(struct device *dev)
>  {
> -	int ret = acpi_lpss_resume(dev);
> +	int ret = acpi_lpss_resume(dev, false);
>  
>  	return ret ? ret : pm_generic_resume_early(dev);
>  }
> @@ -1014,7 +1018,7 @@ static int acpi_lpss_runtime_suspend(str
>  
>  static int acpi_lpss_runtime_resume(struct device *dev)
>  {
> -	int ret = acpi_lpss_resume(dev);
> +	int ret = acpi_lpss_resume(dev, true);
>  
>  	return ret ? ret : pm_generic_runtime_resume(dev);
>  }
> 

-- 
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy