linux-kernel - [PATCH v3 2/3] PCI: PM: Make pci_choose_state() call pci_target

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Message-ID: <5673063.MhkbZ0Pkbq@kreacher>
Date:   Wed, 29 Sep 2021 20:11:18 +0200
From:   "Rafael J. Wysocki" <rjw@...ysocki.net>
To:     Linux ACPI <linux-acpi@...r.kernel.org>,
        Ferry Toth <fntoth@...il.com>
Cc:     Linux PCI <linux-pci@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Bjorn Helgaas <helgaas@...nel.org>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Mika Westerberg <mika.westerberg@...ux.intel.com>
Subject: [PATCH v3 2/3] PCI: PM: Make pci_choose_state() call pci_target_state()

From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>

The pci_choose_state() and pci_target_state() implementations are
somewhat divergent without a good reason, because they are used
for similar purposes.

Change the pci_choose_state() implementation to use pci_target_state()
internally except for transitions to the working state of the system
in which case it is expected to return D0.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---

Same as the v2:

https://patchwork.kernel.org/project/linux-acpi/patch/12860712.dW097sEU6C@kreacher/

---
 drivers/pci/pci-acpi.c |    3 --
 drivers/pci/pci.c      |   54 ++++++++++++++-----------------------------------
 2 files changed, 16 insertions(+), 41 deletions(-)

Index: linux-pm/drivers/pci/pci.c
===================================================================
--- linux-pm.orig/drivers/pci/pci.c
+++ linux-pm/drivers/pci/pci.c
@@ -1394,44 +1394,6 @@ int pci_set_power_state(struct pci_dev *
 }
 EXPORT_SYMBOL(pci_set_power_state);
 
-/**
- * pci_choose_state - Choose the power state of a PCI device
- * @dev: PCI device to be suspended
- * @state: target sleep state for the whole system. This is the value
- *	   that is passed to suspend() function.
- *
- * Returns PCI power state suitable for given device and given system
- * message.
- */
-pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state)
-{
-	pci_power_t ret;
-
-	if (!dev->pm_cap)
-		return PCI_D0;
-
-	ret = platform_pci_choose_state(dev);
-	if (ret != PCI_POWER_ERROR)
-		return ret;
-
-	switch (state.event) {
-	case PM_EVENT_ON:
-		return PCI_D0;
-	case PM_EVENT_FREEZE:
-	case PM_EVENT_PRETHAW:
-		/* REVISIT both freeze and pre-thaw "should" use D0 */
-	case PM_EVENT_SUSPEND:
-	case PM_EVENT_HIBERNATE:
-		return PCI_D3hot;
-	default:
-		pci_info(dev, "unrecognized suspend event %d\n",
-			 state.event);
-		BUG();
-	}
-	return PCI_D0;
-}
-EXPORT_SYMBOL(pci_choose_state);
-
 #define PCI_EXP_SAVE_REGS	7
 
 static struct pci_cap_saved_state *_pci_find_saved_cap(struct pci_dev *pci_dev,
@@ -2843,6 +2805,22 @@ void pci_dev_complete_resume(struct pci_
 	spin_unlock_irq(&dev->power.lock);
 }
 
+/**
+ * pci_choose_state - Choose the power state of a PCI device.
+ * @dev: Target PCI device.
+ * @state: Target state for the whole system.
+ *
+ * Returns PCI power state suitable for @dev and @state.
+ */
+pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state)
+{
+	if (state.event == PM_EVENT_ON)
+		return PCI_D0;
+
+	return pci_target_state(dev, false);
+}
+EXPORT_SYMBOL(pci_choose_state);
+
 void pci_config_pm_runtime_get(struct pci_dev *pdev)
 {
 	struct device *dev = &pdev->dev;
Index: linux-pm/drivers/pci/pci-acpi.c
===================================================================
--- linux-pm.orig/drivers/pci/pci-acpi.c
+++ linux-pm/drivers/pci/pci-acpi.c
@@ -910,9 +910,6 @@ pci_power_t acpi_pci_choose_state(struct
 {
 	int acpi_state, d_max;
 
-	if (acpi_pci_disabled)
-		return PCI_POWER_ERROR;
-
 	if (pdev->no_d3cold)
 		d_max = ACPI_STATE_D3_HOT;
 	else