[PATCH v2 3/6] PCI/PM: Split out code from pci_pm_suspend_noirq() into helper

Mario Limonciello (AMD)
2026-04-27T20:50:37Z

In order to unify suspend and hibernate codepaths without code duplication
the common code should be in common helpers. Move it from
pci_pm_suspend_noirq() into a helper. No intended functional changes.

Tested-by: Eric Naim <dnaim@cachyos.org>
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
---
drivers/pci/pci-driver.c | 86 +++++++++++++++++++++++++---------------
1 file changed, 54 insertions(+), 32 deletions(-)

diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index a43ee7bbfb3f5..bfb521eb0eed7 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -788,6 +788,54 @@ static void pci_pm_complete(struct device *dev)

#endif /* !CONFIG_PM_SLEEP */

+#if defined(CONFIG_SUSPEND)
+/**
+ * pci_pm_suspend_noirq_common
+ * @pci_dev: pci device
+ * @skip_bus_pm: pointer to a boolean indicating whether to skip bus PM
+ *
+ * Prepare the device to go into a low power state by saving state and
+ * deciding whether to skip bus PM.
+ *
+ */
+static void pci_pm_suspend_noirq_common(struct pci_dev *pci_dev, bool *skip_bus_pm)
+{
+ if (!pci_dev->state_saved) {
+ pci_save_state(pci_dev);
+
+ /*
+ * If the device is a bridge with a child in D0 below it,
+ * it needs to stay in D0, so check skip_bus_pm to avoid
+ * putting it into a low-power state in that case.
+ */
+ if (!pci_dev->skip_bus_pm && pci_power_manageable(pci_dev))
+ pci_prepare_to_sleep(pci_dev);
+ }
+
+ pci_dbg(pci_dev, "PCI PM: Sleep power state: %s\n",
+ pci_power_name(pci_dev->current_state));
+
+ if (pci_dev->current_state == PCI_D0) {
+ pci_dev->skip_bus_pm = true;
+ /*
+ * Per PCI PM r1.2, table 6-1, a bridge must be in D0 if any
+ * downstream device is in D0, so avoid changing the power state
+ * of the parent bridge by setting the skip_bus_pm flag for it.
+ */
+ if (pci_dev->bus->self)
+ pci_dev->bus->self->skip_bus_pm = true;
+ }
+
+ if (pci_dev->skip_bus_pm && pm_suspend_no_platform()) {
+ pci_dbg(pci_dev, "PCI PM: Skipped\n");
+ *skip_bus_pm = true;
+ return;
+ }
+
+ pci_pm_set_unknown_state(pci_dev);
+}
+#endif /* CONFIG_SUSPEND */
+
#ifdef CONFIG_SUSPEND
static void pcie_pme_root_status_cleanup(struct pci_dev *pci_dev)
{
@@ -877,6 +925,7 @@ static int pci_pm_suspend_noirq(struct device *dev)
{
struct pci_dev *pci_dev = to_pci_dev(dev);
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+ bool skip_bus_pm = false;

if (dev_pm_skip_suspend(dev))
return 0;
@@ -886,7 +935,8 @@ static int pci_pm_suspend_noirq(struct device *dev)

if (!pm) {
pci_save_state(pci_dev);
- goto set_unknown;
+ pci_pm_set_unknown_state(pci_dev);
+ goto Ehci_workaround;
}

if (pm->suspend_noirq) {
@@ -907,40 +957,12 @@ static int pci_pm_suspend_noirq(struct device *dev)
}
}

- if (!pci_dev->state_saved) {
- pci_save_state(pci_dev);
-
- /*
- * If the device is a bridge with a child in D0 below it,
- * it needs to stay in D0, so check skip_bus_pm to avoid
- * putting it into a low-power state in that case.
- */
- if (!pci_dev->skip_bus_pm && pci_power_manageable(pci_dev))
- pci_prepare_to_sleep(pci_dev);
- }
-
- pci_dbg(pci_dev, "PCI PM: Suspend power state: %s\n",
- pci_power_name(pci_dev->current_state));
+ pci_pm_suspend_noirq_common(pci_dev, &skip_bus_pm);

- if (pci_dev->current_state == PCI_D0) {
- pci_dev->skip_bus_pm = true;
- /*
- * Per PCI PM r1.2, table 6-1, a bridge must be in D0 if any
- * downstream device is in D0, so avoid changing the power state
- * of the parent bridge by setting the skip_bus_pm flag for it.
- */
- if (pci_dev->bus->self)
- pci_dev->bus->self->skip_bus_pm = true;
- }
-
- if (pci_dev->skip_bus_pm && pm_suspend_no_platform()) {
- pci_dbg(pci_dev, "PCI PM: Skipped\n");
+ if (skip_bus_pm)
goto Fixup;
- }
-
-set_unknown:
- pci_pm_set_unknown_state(pci_dev);

+Ehci_workaround:
/*
* Some BIOSes from ASUS have a bug: If a USB EHCI host controller's
* PCI COMMAND register isn't 0, the BIOS assumes that the controller
--
2.53.0