diff mbox series

[4/6] drm/i915/pm: Move the hibernate+D3 quirk stuff into noirq() pm hooks

Message ID 20240925144526.2482-5-ville.syrjala@linux.intel.com (mailing list archive)
State Changes Requested
Headers show
Series drm/i915/pm: Clean up the hibernate vs. PCI D3 quirk | expand

Commit Message

Ville Syrjälä Sept. 25, 2024, 2:45 p.m. UTC 
From: Ville Syrjälä <ville.syrjala@linux.intel.com>

If the driver doesn't call pci_save_state() driver/pci will
normally save+power manage the device from the _noirq() pm
hooks.

We can't let that happen as some old BIOSes fail to hibernate
when the device is in D3. However, we can get a bit closer to
the standard behaviour by doing our explicit pci_save_state()
and pci_set_power_state() stuff from driver provided _noirq()
hooks as well.

This results in a change of behaviur where we no longer go
into D3 at the end of .freeze_late(), so when it comes time
to .thaw() we'll already be in D0, and thus we can drop the
explicit pci_set_power_state(D0) call.

Presumable swictcheroo suspend will want to go into D3 so
call the _noirq() stuff from the switcheroo suspend hook,
and since we dropped the pci_set_power_state(D0) from
.resume_early() we'll need to add one back into the
swtcheroo resume hook.

Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: linux-pci@vger.kernel.org
Cc: intel-gfx@lists.freedesktop.org
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 drivers/gpu/drm/i915/i915_driver.c | 76 ++++++++++++++++++++----------
 1 file changed, 51 insertions(+), 25 deletions(-)

Comments

Bjorn Helgaas Sept. 25, 2024, 7:28 p.m. UTC | #1 
On Wed, Sep 25, 2024 at 05:45:24PM +0300, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> 
> If the driver doesn't call pci_save_state() driver/pci will
> normally save+power manage the device from the _noirq() pm
> hooks.

drivers/pci.  Or maybe just mention the PM hook names specifically.

> We can't let that happen as some old BIOSes fail to hibernate
> when the device is in D3. However, we can get a bit closer to
> the standard behaviour by doing our explicit pci_save_state()
> and pci_set_power_state() stuff from driver provided _noirq()
> hooks as well.
> 
> This results in a change of behaviur where we no longer go
> into D3 at the end of .freeze_late(), so when it comes time
> to .thaw() we'll already be in D0, and thus we can drop the
> explicit pci_set_power_state(D0) call.

s/behaviur/behaviour/

> Presumable swictcheroo suspend will want to go into D3 so
> call the _noirq() stuff from the switcheroo suspend hook,
> and since we dropped the pci_set_power_state(D0) from
> .resume_early() we'll need to add one back into the
> swtcheroo resume hook.

s/swictcheroo/switcheroo/
s/swtcheroo/switcheroo/

Or maybe just use the actual function names here too.  That saves
time for me, at least, because it points me at exactly where to look.

Bjorn
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c
index 1e5abf72dfc4..fe7c34045794 100644
--- a/drivers/gpu/drm/i915/i915_driver.c
+++ b/drivers/gpu/drm/i915/i915_driver.c
@@ -1097,6 +1097,21 @@  static int i915_drm_suspend_late(struct drm_device *dev, bool hibernation)
 
 	pci_disable_device(pdev);
 
+	return 0;
+
+fail:
+	enable_rpm_wakeref_asserts(rpm);
+	if (!dev_priv->uncore.user_forcewake_count)
+		intel_runtime_pm_driver_release(rpm);
+
+	return ret;
+}
+
+static int i915_drm_suspend_noirq(struct drm_device *dev, bool hibernation)
+{
+	struct drm_i915_private *dev_priv = to_i915(dev);
+	struct pci_dev *pdev = to_pci_dev(dev_priv->drm.dev);
+
 	/*
 	 * During hibernation on some platforms the BIOS may try to access
 	 * the device even though it's already in D3 and hang the machine. So
@@ -1117,13 +1132,6 @@  static int i915_drm_suspend_late(struct drm_device *dev, bool hibernation)
 		pci_set_power_state(pdev, PCI_D3hot);
 
 	return 0;
-
-fail:
-	enable_rpm_wakeref_asserts(rpm);
-	if (!dev_priv->uncore.user_forcewake_count)
-		intel_runtime_pm_driver_release(rpm);
-
-	return ret;
 }
 
 int i915_driver_suspend_switcheroo(struct drm_i915_private *i915,
@@ -1142,7 +1150,15 @@  int i915_driver_suspend_switcheroo(struct drm_i915_private *i915,
 	if (error)
 		return error;
 
-	return i915_drm_suspend_late(&i915->drm, false);
+	error = i915_drm_suspend_late(&i915->drm, false);
+	if (error)
+		return error;
+
+	error = i915_drm_suspend_noirq(&i915->drm, false);
+	if (error)
+		return error;
+
+	return 0;
 }
 
 static int i915_drm_resume(struct drm_device *dev)
@@ -1246,23 +1262,6 @@  static int i915_drm_resume_early(struct drm_device *dev)
 	 * similar so that power domains can be employed.
 	 */
 
-	/*
-	 * Note that we need to set the power state explicitly, since we
-	 * powered off the device during freeze and the PCI core won't power
-	 * it back up for us during thaw. Powering off the device during
-	 * freeze is not a hard requirement though, and during the
-	 * suspend/resume phases the PCI core makes sure we get here with the
-	 * device powered on. So in case we change our freeze logic and keep
-	 * the device powered we can also remove the following set power state
-	 * call.
-	 */
-	ret = pci_set_power_state(pdev, PCI_D0);
-	if (ret) {
-		drm_err(&dev_priv->drm,
-			"failed to set PCI D0 power state (%d)\n", ret);
-		return ret;
-	}
-
 	/*
 	 * Note that pci_enable_device() first enables any parent bridge
 	 * device and only then sets the power state for this device. The
@@ -1302,11 +1301,16 @@  static int i915_drm_resume_early(struct drm_device *dev)
 
 int i915_driver_resume_switcheroo(struct drm_i915_private *i915)
 {
+	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
 	int ret;
 
 	if (i915->drm.switch_power_state == DRM_SWITCH_POWER_OFF)
 		return 0;
 
+	ret = pci_set_power_state(pdev, PCI_D0);
+	if (ret)
+		return ret;
+
 	ret = i915_drm_resume_early(&i915->drm);
 	if (ret)
 		return ret;
@@ -1363,6 +1367,16 @@  static int i915_pm_suspend_late(struct device *kdev)
 	return i915_drm_suspend_late(&i915->drm, false);
 }
 
+static int i915_pm_suspend_noirq(struct device *kdev)
+{
+	struct drm_i915_private *i915 = kdev_to_i915(kdev);
+
+	if (i915->drm.switch_power_state == DRM_SWITCH_POWER_OFF)
+		return 0;
+
+	return i915_drm_suspend_noirq(&i915->drm, false);
+}
+
 static int i915_pm_poweroff_late(struct device *kdev)
 {
 	struct drm_i915_private *i915 = kdev_to_i915(kdev);
@@ -1373,6 +1387,16 @@  static int i915_pm_poweroff_late(struct device *kdev)
 	return i915_drm_suspend_late(&i915->drm, true);
 }
 
+static int i915_pm_poweroff_noirq(struct device *kdev)
+{
+	struct drm_i915_private *i915 = kdev_to_i915(kdev);
+
+	if (i915->drm.switch_power_state == DRM_SWITCH_POWER_OFF)
+		return 0;
+
+	return i915_drm_suspend_noirq(&i915->drm, true);
+}
+
 static int i915_pm_resume_early(struct device *kdev)
 {
 	struct drm_i915_private *i915 = kdev_to_i915(kdev);
@@ -1638,6 +1662,7 @@  const struct dev_pm_ops i915_pm_ops = {
 	.prepare = i915_pm_prepare,
 	.suspend = i915_pm_suspend,
 	.suspend_late = i915_pm_suspend_late,
+	.suspend_noirq = i915_pm_suspend_noirq,
 	.resume_early = i915_pm_resume_early,
 	.resume = i915_pm_resume,
 	.complete = i915_pm_complete,
@@ -1663,6 +1688,7 @@  const struct dev_pm_ops i915_pm_ops = {
 	.thaw = i915_pm_thaw,
 	.poweroff = i915_pm_suspend,
 	.poweroff_late = i915_pm_poweroff_late,
+	.poweroff_noirq = i915_pm_poweroff_noirq,
 	.restore_early = i915_pm_restore_early,
 	.restore = i915_pm_restore,