For bridges, have pcie_aspm_init_link_state() allocate a link_state, regardless of whether it currently has any children. pcie_aspm_init_link_state(): Called for bridges (upstream end of link) after all children have been enumerated. No longer needs to check aspm_support_enabled or pdev->has_secondary_link or the VIA quirk: pci_aspm_init() already checked that stuff, so we only need to check pdev->link_state here. Now that we are calling alloc_pcie_link_state() from pci_aspm_init() , get rid of pci_function_0 function and detect downstream link in pci_aspm_init_upstream() instead when the function number is 0. Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=194895 Signed-off-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx> --- drivers/pci/pcie/aspm.c | 72 ++++++++++++++++++++++++------------------------- 1 file changed, 36 insertions(+), 36 deletions(-) diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index a80d64b..e33f84b 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -422,20 +422,6 @@ static void pcie_aspm_check_latency(struct pci_dev *endpoint) } } -/* - * The L1 PM substate capability is only implemented in function 0 in a - * multi function device. - */ -static struct pci_dev *pci_function_0(struct pci_bus *linkbus) -{ - struct pci_dev *child; - - list_for_each_entry(child, &linkbus->devices, bus_list) - if (PCI_FUNC(child->devfn) == 0) - return child; - return NULL; -} - /* Calculate L1.2 PM substate timing parameters */ static void aspm_calc_l1ss_info(struct pcie_link_state *link, struct aspm_register_info *upreg, @@ -798,7 +784,6 @@ static struct pcie_link_state *alloc_pcie_link_state(struct pci_dev *pdev) INIT_LIST_HEAD(&link->children); INIT_LIST_HEAD(&link->link); link->pdev = pdev; - link->downstream = pci_function_0(pdev->subordinate); /* * Root Ports and PCI/PCI-X to PCIe Bridges are roots of PCIe @@ -828,11 +813,33 @@ static struct pcie_link_state *alloc_pcie_link_state(struct pci_dev *pdev) static int pci_aspm_init_downstream(struct pci_dev *pdev) { + struct pcie_link_state *link; + struct pci_dev *parent; + + /* + * The L1 PM substate capability is only implemented in function 0 in a + * multi function device. + */ + if (PCI_FUNC(pdev->devfn) != 0) + return -EINVAL; + + parent = pdev->bus->self; + if (!parent) + return -EINVAL; + + link = parent->link_state; + link->downstream = pdev; return 0; } static int pci_aspm_init_upstream(struct pci_dev *pdev) { + struct pcie_link_state *link; + + link = alloc_pcie_link_state(pdev); + if (!link) + return -ENOMEM; + return 0; } @@ -843,6 +850,17 @@ static int pci_aspm_init_upstream(struct pci_dev *pdev) */ int pci_aspm_init(struct pci_dev *pdev) { + if (!aspm_support_enabled) + return 0; + + if (!pci_is_pcie(pdev)) + return -EINVAL; + + /* VIA has a strange chipset, root port is under a bridge */ + if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT && + pdev->bus->self) + return 0; + if (!pdev->has_secondary_link) return pci_aspm_init_downstream(pdev); @@ -859,33 +877,16 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev) struct pcie_link_state *link; int blacklist = !!pcie_aspm_sanity_check(pdev); - if (!aspm_support_enabled) - return; - - if (pdev->link_state) - return; - - /* - * We allocate pcie_link_state for the component on the upstream - * end of a Link, so there's nothing to do unless this device has a - * Link on its secondary side. - */ - if (!pdev->has_secondary_link) - return; - - /* VIA has a strange chipset, root port is under a bridge */ - if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT && - pdev->bus->self) + if (!pdev->link_state) return; + link = pdev->link_state; down_read(&pci_bus_sem); if (list_empty(&pdev->subordinate->devices)) goto out; mutex_lock(&aspm_lock); - link = alloc_pcie_link_state(pdev); - if (!link) - goto unlock; + /* * Setup initial ASPM state. Note that we need to configure * upstream links also because capable state of them can be @@ -910,7 +911,6 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev) pcie_set_clkpm(link, policy_to_clkpm_state(link)); } -unlock: mutex_unlock(&aspm_lock); out: up_read(&pci_bus_sem); -- 1.9.1
