From: Kai-Heng Feng <kai.heng.feng@canonical.com>

Date: Mon, 11 Jul 2022 18:07:01 -0500

Subject: PCI/ASPM: Remove pcie_aspm_pm_state_change()

Git-commit: 08d0cc5f34265d1a1e3031f319f594bd1970976c

Patch-mainline: 6.0-rc1

References: git-fixes

pcie_aspm_pm_state_change() was introduced at the inception of PCIe ASPM

code, but it can cause some issues. For instance, when ASPM config is

changed via sysfs, those changes won't persist across power state change

because pcie_aspm_pm_state_change() overwrites them.

Also, if the driver restores L1SS [1] after system resume, the restored

state will also be overwritten by pcie_aspm_pm_state_change().

Remove pcie_aspm_pm_state_change().  If there's any hardware that really

needs it to function, a quirk can be used instead.

[js] no pcie_aspm_pm_state_change() in pci_set_low_power_state(), see below.

[1] https://lore.kernel.org/linux-pci/20220201123536.12962-1-vidyas@nvidia.com/

Link: https://lore.kernel.org/r/20220509073639.2048236-1-kai.heng.feng@canonical.com

[bhelgaas: remove additional pcie_aspm_pm_state_change() call in

pci_set_low_power_state(), added by

10aa5377fc8a ("PCI/PM: Split pci_raw_set_power_state()") and moved by

7957d201456f ("PCI/PM: Relocate pci_set_low_power_state()")]

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Signed-off-by: Jiri Slaby <jslaby@suse.cz>

---

 drivers/pci/pci.c       |    3 ---

 drivers/pci/pci.h       |    2 --

 drivers/pci/pcie/aspm.c |   19 -------------------

 3 files changed, 24 deletions(-)

--- a/drivers/pci/pci.c

+++ b/drivers/pci/pci.c

@@ -1160,9 +1160,6 @@ static int pci_raw_set_power_state(struc

 	if (need_restore)

 		pci_restore_bars(dev);

-	if (dev->bus->self)

-		pcie_aspm_pm_state_change(dev->bus->self);

-

 	return 0;

 }

--- a/drivers/pci/pci.h

+++ b/drivers/pci/pci.h

@@ -598,12 +598,10 @@ bool pcie_wait_for_link(struct pci_dev *

 #ifdef CONFIG_PCIEASPM

 void pcie_aspm_init_link_state(struct pci_dev *pdev);

 void pcie_aspm_exit_link_state(struct pci_dev *pdev);

-void pcie_aspm_pm_state_change(struct pci_dev *pdev);

 void pcie_aspm_powersave_config_link(struct pci_dev *pdev);

 #else

 static inline void pcie_aspm_init_link_state(struct pci_dev *pdev) { }

 static inline void pcie_aspm_exit_link_state(struct pci_dev *pdev) { }

-static inline void pcie_aspm_pm_state_change(struct pci_dev *pdev) { }

 static inline void pcie_aspm_powersave_config_link(struct pci_dev *pdev) { }

 #endif

--- a/drivers/pci/pcie/aspm.c

+++ b/drivers/pci/pcie/aspm.c

@@ -1020,25 +1020,6 @@ out:

 	up_read(&pci_bus_sem);

 }

-/* @pdev: the root port or switch downstream port */

-void pcie_aspm_pm_state_change(struct pci_dev *pdev)

-{

-	struct pcie_link_state *link = pdev->link_state;

-

-	if (aspm_disabled || !link)

-		return;

-	/*

-	 * Devices changed PM state, we should recheck if latency

-	 * meets all functions' requirement

-	 */

-	down_read(&pci_bus_sem);

-	mutex_lock(&aspm_lock);

-	pcie_update_aspm_capable(link->root);

-	pcie_config_aspm_path(link);

-	mutex_unlock(&aspm_lock);

-	up_read(&pci_bus_sem);

-}

-

 void pcie_aspm_powersave_config_link(struct pci_dev *pdev)

 {

 	struct pcie_link_state *link = pdev->link_state;