From: Mika Westerberg <mika.westerberg@linux.intel.com>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Linux PM <linux-pm@vger.kernel.org>,
Linux PCI <linux-pci@vger.kernel.org>,
Linux ACPI <linux-acpi@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Bjorn Helgaas <helgaas@kernel.org>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Hans De Goede <hdegoede@redhat.com>,
"Robert R. Howell" <RHowell@uwyo.edu>
Subject: Re: [PATCH v2 1/5] PM: ACPI/PCI: Resume all devices during hibernation
Date: Mon, 1 Jul 2019 19:15:50 +0300 [thread overview]
Message-ID: <20190701161550.GA2640@lahna.fi.intel.com> (raw)
In-Reply-To: <6191578.xJk2HsE5MX@kreacher>
On Mon, Jul 01, 2019 at 12:44:25PM +0200, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> Both the PCI bus type and the ACPI PM domain avoid resuming
> runtime-suspended devices with DPM_FLAG_SMART_SUSPEND set during
> hibernation (before creating the snapshot image of system memory),
> but that turns out to be a mistake. It leads to functional issues
> and adds complexity that's hard to justify.
>
> For this reason, resume all runtime-suspended PCI devices and all
> devices in the ACPI PM domains before creating a snapshot image of
> system memory during hibernation.
>
> Fixes: 05087360fd7a (ACPI / PM: Take SMART_SUSPEND driver flag into account)
> Fixes: c4b65157aeef (PCI / PM: Take SMART_SUSPEND driver flag into account)
> Link: https://lore.kernel.org/linux-acpi/917d4399-2e22-67b1-9d54-808561f9083f@uwyo.edu/T/#maf065fe6e4974f2a9d79f332ab99dfaba635f64c
> Reported-by: Robert R. Howell <RHowell@uwyo.edu>
> Tested-by: Robert R. Howell <RHowell@uwyo.edu>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
>
> -> v2: No changes.
>
> ---
> drivers/acpi/device_pm.c | 13 +++++++------
> drivers/pci/pci-driver.c | 16 ++++++++--------
> 2 files changed, 15 insertions(+), 14 deletions(-)
>
> Index: linux-pm/drivers/acpi/device_pm.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/device_pm.c
> +++ linux-pm/drivers/acpi/device_pm.c
> @@ -1155,13 +1155,14 @@ EXPORT_SYMBOL_GPL(acpi_subsys_resume_ear
> int acpi_subsys_freeze(struct device *dev)
> {
> /*
> - * This used to be done in acpi_subsys_prepare() for all devices and
> - * some drivers may depend on it, so do it here. Ideally, however,
> - * runtime-suspended devices should not be touched during freeze/thaw
> - * transitions.
> + * 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 they need to be
> + * put into the runtime-active metastate during system resume anyway,
> + * so it is better to ensure that the state saved in the image will be
> + * alwyas consistent with that.
alwyas -> always
> */
> - if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND))
> - pm_runtime_resume(dev);
> + pm_runtime_resume(dev);
>
> return pm_generic_freeze(dev);
> }
> Index: linux-pm/drivers/pci/pci-driver.c
> ===================================================================
> --- linux-pm.orig/drivers/pci/pci-driver.c
> +++ linux-pm/drivers/pci/pci-driver.c
> @@ -1012,15 +1012,15 @@ 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 they need to be
> + * put into the runtime-active metastate during system resume anyway,
> + * so it is better to ensure that the state saved in the image will be
> + * alwyas consistent with that.
ditto
> */
> - 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;
>
>
>
next prev parent reply other threads:[~2019-07-01 16:15 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-01 10:42 [PATCH v2 0/5] PM: PCI/ACPI: Hibernation handling fixes Rafael J. Wysocki
2019-07-01 10:44 ` [PATCH v2 1/5] PM: ACPI/PCI: Resume all devices during hibernation Rafael J. Wysocki
2019-07-01 16:15 ` Mika Westerberg [this message]
2019-07-02 15:59 ` Rafael J. Wysocki
2019-07-02 4:24 ` Robert R. Howell
2019-07-01 10:46 ` [PATCH v2 2/5] PCI: PM: Simplify bus-level hibernation callbacks Rafael J. Wysocki
2019-07-01 10:54 ` [PATCH v2 3/5] ACPI: PM: Simplify and fix PM domain " Rafael J. Wysocki
2019-07-01 10:54 ` [PATCH v2 4/5] ACPI: PM: Introduce "poweroff" callbacks for ACPI PM domain and LPSS Rafael J. Wysocki
2019-07-01 10:55 ` [PATCH v2 5/5] ACPI: PM: Drop unused function and function header Rafael J. Wysocki
2019-07-01 11:30 ` [PATCH v2 0/5] PM: PCI/ACPI: Hibernation handling fixes Hans de Goede
2019-07-01 16:20 ` Mika Westerberg
2019-07-05 9:50 ` Rafael J. Wysocki
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