linux-kernel - [PATCH 3/6] PCI/PM: Simplify pci_set_power

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Date:   Fri,  1 Nov 2019 15:45:55 -0500
From:   Bjorn Helgaas <helgaas@...nel.org>
To:     linux-pci@...r.kernel.org
Cc:     "Rafael J . Wysocki" <rafael.j.wysocki@...el.com>,
        linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
        Bjorn Helgaas <bhelgaas@...gle.com>
Subject: [PATCH 3/6] PCI/PM: Simplify pci_set_power_state()

From: Bjorn Helgaas <bhelgaas@...gle.com>

Check for the PCI_DEV_FLAGS_NO_D3 quirk early, before calling
__pci_start_power_transition().  This way all the cases where we don't need
to do anything at all are checked up front.

This doesn't fix anything because if the caller requested D3hot or D3cold,
__pci_start_power_transition() is a no-op.  But calling it is pointless and
makes the code harder to analyze.

Signed-off-by: Bjorn Helgaas <bhelgaas@...gle.com>
---
 drivers/pci/pci.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index a9d3653ef960..281bc8fc51b3 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1130,8 +1130,6 @@ int pci_set_power_state(struct pci_dev *dev, pci_power_t state)
 	if (dev->current_state == state)
 		return 0;
 
-	__pci_start_power_transition(dev, state);
-
 	/*
 	 * This device is quirked not to be put into D3, so don't put it in
 	 * D3
@@ -1139,6 +1137,8 @@ int pci_set_power_state(struct pci_dev *dev, pci_power_t state)
 	if (state >= PCI_D3hot && (dev->dev_flags & PCI_DEV_FLAGS_NO_D3))
 		return 0;
 
+	__pci_start_power_transition(dev, state);
+
 	/*
 	 * To put device in D3cold, we put device into D3hot in native
 	 * way, then put device into D3cold with platform ops
-- 
2.24.0.rc1.363.gb1bccd3e3d-goog