From 1a680b7c325882188865f05b9a88d32f75f26495 Mon Sep 17 00:00:00 2001 From: Naga Chumbalkar Date: Mon, 21 Mar 2011 03:29:08 +0000 Subject: PCI: PCIe links may not get configured for ASPM under POWERSAVE mode v3 -> v2: Moved ASPM enabling logic to pci_set_power_state() v2 -> v1: Preserved the logic in pci_raw_set_power_state() : Added ASPM enabling logic after scanning Root Bridge : http://marc.info/?l=linux-pci&m=130046996216391&w=2 v1 : http://marc.info/?l=linux-pci&m=130013164703283&w=2 The assumption made in commit 41cd766b065970ff6f6c89dd1cf55fa706c84a3d (PCI: Don't enable aspm before drivers have had a chance to veto it) that pci_enable_device() will result in re-configuring ASPM when aspm_policy is POWERSAVE is no longer valid. This is due to commit 97c145f7c87453cec90e91238fba5fe2c1561b32 (PCI: read current power state at enable time) which resets dev->current_state to D0. Due to this the call to pcie_aspm_pm_state_change() is never made. Note the equality check (below) that returns early: ./drivers/pci/pci.c: pci_raw_set_pci_power_state() 546 /* Check if we're already there */ 547 if (dev->current_state == state) 548 return 0; Therefore OSPM never configures the PCIe links for ASPM to turn them "on". Fix it by configuring ASPM from the pci_enable_device() code path. This also allows a driver such as the e1000e networking driver a chance to disable ASPM (L0s, L1), if need be, prior to enabling the device. A driver may perform this action if the device is known to mis-behave wrt ASPM. Signed-off-by: Naga Chumbalkar Acked-by: Rafael J. Wysocki Cc: Matthew Garrett Signed-off-by: Jesse Barnes --- include/linux/pci-aspm.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux/pci-aspm.h') diff --git a/include/linux/pci-aspm.h b/include/linux/pci-aspm.h index ce6810512c66..67cb3ae38016 100644 --- a/include/linux/pci-aspm.h +++ b/include/linux/pci-aspm.h @@ -26,6 +26,7 @@ extern void pcie_aspm_init_link_state(struct pci_dev *pdev); extern void pcie_aspm_exit_link_state(struct pci_dev *pdev); extern void pcie_aspm_pm_state_change(struct pci_dev *pdev); +extern void pcie_aspm_powersave_config_link(struct pci_dev *pdev); extern void pci_disable_link_state(struct pci_dev *pdev, int state); extern void pcie_clear_aspm(void); extern void pcie_no_aspm(void); @@ -39,6 +40,9 @@ 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) +{ +} static inline void pci_disable_link_state(struct pci_dev *pdev, int state) { } -- cgit