Re: [PATCH] ACPI / LPSS: Don't skip late system PM ops for hibernate on BYT/CHT

From: Rafael J. Wysocki
Date: Mon Jun 24 2019 - 06:24:25 EST

On Saturday, May 25, 2019 7:31:20 AM CEST Robert R. Howell wrote:
> On 5/16/19 5:11 AM, Rafael J. Wysocki wrote:
> >
> > On Thursday, April 25, 2019 6:38:34 PM CEST Robert R. Howell wrote:
> >> On 4/24/19 1:20 AM, Rafael J. Wysocki wrote:
> >>
> >>> On Tue, Apr 23, 2019 at 10:03 PM Robert R. Howell <RHowell@xxxxxxxx> wrote:
> >>>>
> >>>> On 4/23/19 2:07 AM, Rafael J. Wysocki wrote:
> >>>>>
> >>>>> On Sat, Apr 20, 2019 at 12:44 AM Robert R. Howell <RHowell@xxxxxxxx> wrote:
> >>>>>>
> >>>>>> On 4/18/19 5:42 AM, Hans de Goede wrote:
> >>>>>>
> >>>>>>>> On 4/8/19 2:16 AM, Hans de Goede wrote:>
> >>>>>>>>>
> >>>>>>>>> Hmm, interesting so you have hibernation working on a T100TA
> >>>>>>>>> (with 5.0 + 02e45646d53b reverted), right ?
> >>>>>>>>>
> >>>>>>
> >>>>>>
> >>>>>> I've managed to find a way around the i2c_designware timeout issues
> >>>>>> on the T100TA's. The key is to NOT set DPM_FLAG_SMART_SUSPEND,
> >>>>>> which was added in the 02e45646d53b commit.
> >>>>>>
> >>>>>> To test that I've started with a 5.1-rc5 kernel, applied your recent patch
> >>>>>> to acpi_lpss.c, then apply the following patch of mine, removing
> >>>>>> DPM_FLAG_SMART_SUSPEND. (For the T100 hardware I need to apply some
> >>>>>> other patches as well but those are not related to the i2c-designware or
> >>>>>> acpi issues addressed here.)
> >>>>>>
> >>>>>> On a resume from hibernation I still see one error:
> >>>>>> "i2c_designware 80860F41:00: Error i2c_dw_xfer called while suspended"
> >>>>>> but I no longer get the i2c_designware timeouts, and audio does now work
> >>>>>> after the resume.
> >>>>>>
> >>>>>> Removing DPM_FLAG_SMART_SUSPEND may not be what you want for other
> >>>>>> hardware, but perhaps this will give you a clue as to what is going
> >>>>>> wrong with hibernate/resume on the T100TA's.
> >>>>>
> >>>>> What if you drop DPM_FLAG_LEAVE_SUSPENDED alone instead?
> >>>>>
> >>>>
> >>>> I did try dropping just DPM_FLAG_LEAVE_SUSPENDED, dropping just
> >>>> DPM_FLAG_SMART_SUSPEND, and dropping both flags. When I just drop
> >>>> DPM_FLAG_LEAVE_SUSPENDED I still get the i2c_designware timeouts
> >>>> after the resume. If I drop just DPM_FLAG_SMART_SUSPEND or drop both,
> >>>> then the timeouts go away.
> >>>
> >>> OK, thanks!
> >>>
> >>> Is non-hibernation system suspend affected too?
> >>
> >> I just ran some tests on a T100TA, using the 5.1-rc5 code with Hans' patch applied
> >> but without any changes to i2c-designware-platdrv.c, so the
> >> DPM_FLAG_SMART_PREPARE, DPM_FLAG_SMART_SUSPEND, and DPM_FLAG_LEAVE_SUSPENDED flags
> >> are all set.
> >>
> >> Suspend does work OK, and after resume I do NOT get any of the crippling
> >> i2c_designware timeout errors which cause sound to fail after hibernate. I DO see one
> >> "i2c_designware 80860F41:00: Error i2c_dw_xfer call while suspended"
> >> error on resume, just as I do on hibernate. I've attached a portion of dmesg below.
> >> The "asus_wmi: Unknown key 79 pressed" error is a glitch which occurs
> >> intermittently on these machines, but doesn't seem related to the other issues.
> >> I had one test run when it was absent but the rest of the messages were the
> >> same -- but then kept getting that unknown key error on all my later tries.
> >>
> >> I did notice the "2sidle" in the following rather than "shallow" or "deep". A
> >> cat of /sys/power/state shows "freeze mem disk" but a
> >> cat of /sys/power/mem_sleep" shows only "[s2idle] so it looks like shallow and deep
> >> are not enabled for this system. I did check the input power (or really current)
> >> as it went into suspend and the micro-usb power input drops from about
> >> 0.5 amps to 0.05 amps. But clearly a lot of devices are still active, as movement
> >> of a bluetooth mouse (the MX Anywhere 2) will wake it from suspend. That presumably is
> >> why suspend doesn't trigger the same i2c_designware problems as hibernate.
> >>
> >> Let me know if I can do any other tests.
> >
> > Can you please check if the appended patch makes the hibernate issue go away for you, without any other changes?
> >
> > ---
> > drivers/pci/pci-driver.c | 36 ++++++++++--------------------------
> > 1 file changed, 10 insertions(+), 26 deletions(-)
> >
> > Index: linux-pm/drivers/pci/pci-driver.c
> > ===================================================================
> > --- linux-pm.orig/drivers/pci/pci-driver.c
> > +++ linux-pm/drivers/pci/pci-driver.c
> > @@ -957,15 +957,14 @@ static int pci_pm_freeze(struct device *
> > }
> >
> > /*
> > - * This used to be done in pci_pm_prepare() for all devices and some
> > - * drivers may depend on it, so do it here. Ideally, runtime-suspended
> > - * devices should not be touched during freeze/thaw transitions,
> > - * however.
> > + * Resume all runtime-suspended devices before creating a snapshot
> > + * image of system memory, because the restore kernel generally cannot
> > + * be expected to always handle them consistently and pci_pm_restore()
> > + * always leaves them as "active", so ensure that the state saved in the
> > + * image will always be consistent with that.
> > */
> > - if (!dev_pm_smart_suspend_and_suspended(dev)) {
> > - pm_runtime_resume(dev);
> > - pci_dev->state_saved = false;
> > - }
> > + pm_runtime_resume(dev);
> > + pci_dev->state_saved = false;
> >
> > if (pm->freeze) {
> > int error;
> > @@ -992,9 +991,6 @@ static int pci_pm_freeze_noirq(struct de
> > struct pci_dev *pci_dev = to_pci_dev(dev);
> > struct device_driver *drv = dev->driver;
> >
> > - if (dev_pm_smart_suspend_and_suspended(dev))
> > - return 0;
> > -
> > if (pci_has_legacy_pm_support(pci_dev))
> > return pci_legacy_suspend_late(dev, PMSG_FREEZE);
> >
> > @@ -1024,16 +1020,6 @@ static int pci_pm_thaw_noirq(struct devi
> > struct device_driver *drv = dev->driver;
> > int error = 0;
> >
> > - /*
> > - * If the device is in runtime suspend, the code below may not work
> > - * correctly with it, so skip that code and make the PM core skip all of
> > - * the subsequent "thaw" callbacks for the device.
> > - */
> > - if (dev_pm_smart_suspend_and_suspended(dev)) {
> > - dev_pm_skip_next_resume_phases(dev);
> > - return 0;
> > - }
> > -
> > if (pcibios_pm_ops.thaw_noirq) {
> > error = pcibios_pm_ops.thaw_noirq(dev);
> > if (error)
> > @@ -1093,8 +1079,10 @@ static int pci_pm_poweroff(struct device
> >
> > /* The reason to do that is the same as in pci_pm_suspend(). */
> > if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) ||
> > - !pci_dev_keep_suspended(pci_dev))
> > + !pci_dev_keep_suspended(pci_dev)) {
> > pm_runtime_resume(dev);
> > + pci_dev->state_saved = false;
> > + }
> >
> > pci_dev->state_saved = false;
> > if (pm->poweroff) {
> > @@ -1168,10 +1156,6 @@ static int pci_pm_restore_noirq(struct d
> > struct device_driver *drv = dev->driver;
> > int error = 0;
> >
> > - /* This is analogous to the pci_pm_resume_noirq() case. */
> > - if (dev_pm_smart_suspend_and_suspended(dev))
> > - pm_runtime_set_active(dev);
> > -
> > if (pcibios_pm_ops.restore_noirq) {
> > error = pcibios_pm_ops.restore_noirq(dev);
> > if (error)
> >
> >
> >
>
> I've finally managed to complete a reasonable set of tests on my T100TA using your
> 2nd patch from above, and on a 5.1.4 based kernel with ONLY this patch applied I can
> successfully suspend and hibernate the system.

Sorry for the long delay.

I haven't dropped this issue on the floor, I hope that you are still able to follow up here.

Can you please test the appended patch instead of the previous one?

I have found some inconsistencies in the handling of hibernation in the ACPI PM domain
and the LPSS driver that should be covered by this patch.

---
drivers/acpi/acpi_lpss.c | 63 +++++++++++++++++++++++++++++++++++------------
drivers/acpi/device_pm.c | 30 ++++++++++++++++++++--
include/linux/acpi.h | 4 ++
3 files changed, 79 insertions(+), 18 deletions(-)

Index: linux-pm/drivers/acpi/device_pm.c
===================================================================
--- linux-pm.orig/drivers/acpi/device_pm.c
+++ linux-pm/drivers/acpi/device_pm.c
@@ -1171,6 +1171,32 @@ int acpi_subsys_thaw_noirq(struct device
return pm_generic_thaw_noirq(dev);
}
EXPORT_SYMBOL_GPL(acpi_subsys_thaw_noirq);
+
+/**
+ * acpi_subsys_restore_noirq - Run the device driver's "noirq" restore callback.
+ * @dev: Device to handle.
+ */
+int acpi_subsys_restore_noirq(struct device *dev)
+{
+ /* This is analogous to what acpi_subsys_resune_noirq() does. */
+ if (dev_pm_smart_suspend_and_suspended(dev))
+ pm_runtime_set_active(dev);
+
+ return pm_generic_restore_noirq(dev);
+}
+EXPORT_SYMBOL_GPL(acpi_subsys_restore_noirq);
+
+/**
+ * acpi_subsys_restore_early - Restore device using ACPI.
+ * @dev: Device to restore.
+ */
+int acpi_subsys_restore_early(struct device *dev)
+{
+ int ret = acpi_dev_resume(dev);
+ return ret ? ret : pm_generic_restore_early(dev);
+}
+EXPORT_SYMBOL_GPL(acpi_subsys_restore_early);
+
#endif /* CONFIG_PM_SLEEP */

static struct dev_pm_domain acpi_general_pm_domain = {
@@ -1192,8 +1218,8 @@ static struct dev_pm_domain acpi_general
.poweroff = acpi_subsys_suspend,
.poweroff_late = acpi_subsys_suspend_late,
.poweroff_noirq = acpi_subsys_suspend_noirq,
- .restore_noirq = acpi_subsys_resume_noirq,
- .restore_early = acpi_subsys_resume_early,
+ .restore_noirq = acpi_subsys_restore_noirq,
+ .restore_early = acpi_subsys_restore_early,
#endif
},
};
Index: linux-pm/drivers/acpi/acpi_lpss.c
===================================================================
--- linux-pm.orig/drivers/acpi/acpi_lpss.c
+++ linux-pm/drivers/acpi/acpi_lpss.c
@@ -1069,36 +1069,67 @@ static int acpi_lpss_suspend_noirq(struc
return acpi_subsys_suspend_noirq(dev);
}

-static int acpi_lpss_do_resume_early(struct device *dev)
+static int acpi_lpss_resume_noirq(struct device *dev)
{
- int ret = acpi_lpss_resume(dev);
+ struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
+
+ /* Follow acpi_subsys_resune_noirq(). */
+ if (dev_pm_may_skip_resume(dev))
+ return 0;
+
+ if (dev_pm_smart_suspend_and_suspended(dev))
+ pm_runtime_set_active(dev);

- return ret ? ret : pm_generic_resume_early(dev);
+ if (pdata->dev_desc->resume_from_noirq) {
+ int ret = acpi_lpss_resume(dev);
+ if (ret)
+ return ret;
+ }
+
+ return pm_generic_resume_noirq(dev);
}

static int acpi_lpss_resume_early(struct device *dev)
{
struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));

- if (pdata->dev_desc->resume_from_noirq)
- return 0;
+ if (!pdata->dev_desc->resume_from_noirq) {
+ int ret = acpi_lpss_resume(dev);
+ if (ret)
+ return ret;
+ }

- return acpi_lpss_do_resume_early(dev);
+ return pm_generic_resume_early(dev);
}

-static int acpi_lpss_resume_noirq(struct device *dev)
+static int acpi_lpss_restore_noirq(struct device *dev)
{
struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
- int ret;

- ret = acpi_subsys_resume_noirq(dev);
- if (ret)
- return ret;
+ /* Follow acpi_subsys_restore_noirq(). */
+ if (dev_pm_smart_suspend_and_suspended(dev))
+ pm_runtime_set_active(dev);
+
+ if (pdata->dev_desc->resume_from_noirq) {
+ int ret = acpi_lpss_resume(dev);
+ if (ret)
+ return ret;
+ }
+
+ return pm_generic_restore_noirq(dev);
+}
+
+static int acpi_lpss_restore_early(struct device *dev)
+{
+ struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));

- if (!dev_pm_may_skip_resume(dev) && pdata->dev_desc->resume_from_noirq)
- ret = acpi_lpss_do_resume_early(dev);
+ if (!pdata->dev_desc->resume_from_noirq) {
+ int ret = acpi_lpss_resume(dev);
+ if (ret)
+ return ret;
+ }

- return ret;
+ return pm_generic_restore_early(dev);
}

#endif /* CONFIG_PM_SLEEP */
@@ -1140,8 +1171,8 @@ static struct dev_pm_domain acpi_lpss_pm
.poweroff = acpi_subsys_suspend,
.poweroff_late = acpi_lpss_suspend_late,
.poweroff_noirq = acpi_lpss_suspend_noirq,
- .restore_noirq = acpi_lpss_resume_noirq,
- .restore_early = acpi_lpss_resume_early,
+ .restore_noirq = acpi_lpss_restore_noirq,
+ .restore_early = acpi_lpss_restore_early,
#endif
.runtime_suspend = acpi_lpss_runtime_suspend,
.runtime_resume = acpi_lpss_runtime_resume,
Index: linux-pm/include/linux/acpi.h
===================================================================
--- linux-pm.orig/include/linux/acpi.h
+++ linux-pm/include/linux/acpi.h
@@ -925,6 +925,8 @@ int acpi_subsys_freeze(struct device *de
int acpi_subsys_freeze_late(struct device *dev);
int acpi_subsys_freeze_noirq(struct device *dev);
int acpi_subsys_thaw_noirq(struct device *dev);
+int acpi_subsys_restore_noirq(struct device *dev);
+int acpi_subsys_restore_early(struct device *dev);
#else
static inline int acpi_dev_resume_early(struct device *dev) { return 0; }
static inline int acpi_subsys_prepare(struct device *dev) { return 0; }
@@ -938,6 +940,8 @@ static inline int acpi_subsys_freeze(str
static inline int acpi_subsys_freeze_late(struct device *dev) { return 0; }
static inline int acpi_subsys_freeze_noirq(struct device *dev) { return 0; }
static inline int acpi_subsys_thaw_noirq(struct device *dev) { return 0; }
+static inline int acpi_subsys_restore_noirq(struct device *dev) { return 0; }
+static inline int acpi_subsys_restore_early(struct device *dev) { return 0; }
#endif

#ifdef CONFIG_ACPI