From 1f6ae47ecff7f23da73417e068018b311f3b5583 Mon Sep 17 00:00:00 2001 From: Vidya Sagar Date: Wed, 16 Jul 2014 15:33:42 +0530 Subject: [PATCH] PCI: Configure ASPM when enabling device We can't do ASPM configuration at enumeration-time because enabling it makes some defective hardware unresponsive, even if ASPM is disabled later (see 41cd766b0659 ("PCI: Don't enable aspm before drivers have had a chance to veto it"). Therefore, we have to do it after a driver claims the device. We previously configured ASPM in pci_set_power_state(), but that's not a very good place because it's not really related to setting the PCI device power state, and doing it there means: - We incorrectly skipped ASPM config when setting a device that's already in D0 to D0. - We unnecessarily configured ASPM when setting a device to a low-power state (the ASPM feature only applies when the device is in D0). - We unnecessarily configured ASPM when called from a .resume() method (ASPM configuration needs to be restored during resume, but pci_restore_pcie_state() should already do this). Move ASPM configuration from pci_set_power_state() to do_pci_enable_device() so we do it when a driver enables a device. [bhelgaas: changelog] Link: https://bugzilla.kernel.org/show_bug.cgi?id=79621 Fixes: db288c9c5f9d ("PCI / PM: restore the original behavior of pci_set_power_state()") Suggested-by: Bjorn Helgaas Signed-off-by: Vidya Sagar Signed-off-by: Bjorn Helgaas CC: stable@vger.kernel.org # v3.6+ --- drivers/pci/pci.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 63a54a340863..75fabd1f72bc 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -839,12 +839,6 @@ int pci_set_power_state(struct pci_dev *dev, pci_power_t state) if (!__pci_complete_power_transition(dev, state)) error = 0; - /* - * When aspm_policy is "powersave" this call ensures - * that ASPM is configured. - */ - if (!error && dev->bus->self) - pcie_aspm_powersave_config_link(dev->bus->self); return error; } @@ -1195,12 +1189,18 @@ int __weak pcibios_enable_device(struct pci_dev *dev, int bars) static int do_pci_enable_device(struct pci_dev *dev, int bars) { int err; + struct pci_dev *bridge; u16 cmd; u8 pin; err = pci_set_power_state(dev, PCI_D0); if (err < 0 && err != -EIO) return err; + + bridge = pci_upstream_bridge(dev); + if (bridge) + pcie_aspm_powersave_config_link(bridge); + err = pcibios_enable_device(dev, bars); if (err < 0) return err; -- 2.39.2