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

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Message-ID: <1855125.Q8EGVqeZWv@aspire.rjw.lan>
Date:   Tue, 24 Jul 2018 12:36:47 +0200
From:   "Rafael J. Wysocki" <rjw@...ysocki.net>
To:     Kai Heng Feng <kai.heng.feng@...onical.com>
Cc:     ACPI Devel Maling List <linux-acpi@...r.kernel.org>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        P HeLiOn <perryhelionsemail@...il.com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Mika Westerberg <mika.westerberg@...ux.intel.com>,
        Linux PM <linux-pm@...r.kernel.org>
Subject: Re: [PATCH] ACPI / LPSS: Avoid PM quirks on suspend and resume from S3

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@...ysocki.net> wrote:
> > >
> > > From: Rafael J. Wysocki <rafael.j.wysocki@...el.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.
> > 
> > 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:

---
 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);
 }