From 08d0cc5f34265d1a1e3031f319f594bd1970976c Mon Sep 17 00:00:00 2001 From: Kai-Heng Feng Date: Mon, 11 Jul 2022 18:07:01 -0500 Subject: [PATCH] PCI/ASPM: Remove pcie_aspm_pm_state_change() 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. [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 Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.c | 6 ------ drivers/pci/pci.h | 2 -- drivers/pci/pcie/aspm.c | 19 ------------------- 3 files changed, 27 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index cfaf40a540a8..093303c27ea8 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1293,9 +1293,6 @@ static int pci_set_full_power_state(struct pci_dev *dev) pci_restore_bars(dev); } - if (dev->bus->self) - pcie_aspm_pm_state_change(dev->bus->self); - return 0; } @@ -1390,9 +1387,6 @@ static int pci_set_low_power_state(struct pci_dev *dev, pci_power_t state) pci_power_name(dev->current_state), pci_power_name(state)); - if (dev->bus->self) - pcie_aspm_pm_state_change(dev->bus->self); - return 0; } diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index e10cdec6c56e..785f31086313 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -560,12 +560,10 @@ bool pcie_wait_for_link(struct pci_dev *pdev, bool active); #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 diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index a96b7424c9bc..7f76a5875feb 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -1012,25 +1012,6 @@ 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;