diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 3078de668f91..4a2c229205fd 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -249,7 +249,7 @@ static int pcie_retrain_link(struct pcie_link_state *link) static void pcie_aspm_configure_common_clock(struct pcie_link_state *link) { int same_clock = 1; - u16 reg16, parent_reg, child_reg[8]; + u16 reg16, ccc, parent_old_ccc, child_old_ccc[8]; struct pci_dev *child, *parent = link->pdev; struct pci_bus *linkbus = parent->subordinate; /* @@ -271,6 +271,7 @@ static void pcie_aspm_configure_common_clock(struct pcie_link_state *link) /* Port might be already in common clock mode */ pcie_capability_read_word(parent, PCI_EXP_LNKCTL, ®16); + parent_old_ccc = reg16 & PCI_EXP_LNKCTL_CCC; if (same_clock && (reg16 & PCI_EXP_LNKCTL_CCC)) { bool consistent = true; @@ -287,34 +288,29 @@ static void pcie_aspm_configure_common_clock(struct pcie_link_state *link) pci_info(parent, "ASPM: current common clock configuration is inconsistent, reconfiguring\n"); } + ccc = same_clock ? PCI_EXP_LNKCTL_CCC : 0; /* Configure downstream component, all functions */ list_for_each_entry(child, &linkbus->devices, bus_list) { pcie_capability_read_word(child, PCI_EXP_LNKCTL, ®16); - child_reg[PCI_FUNC(child->devfn)] = reg16; - if (same_clock) - reg16 |= PCI_EXP_LNKCTL_CCC; - else - reg16 &= ~PCI_EXP_LNKCTL_CCC; - pcie_capability_write_word(child, PCI_EXP_LNKCTL, reg16); + child_old_ccc[PCI_FUNC(child->devfn)] = reg16 & PCI_EXP_LNKCTL_CCC; + pcie_capability_clear_and_set_word(child, PCI_EXP_LNKCTL, + PCI_EXP_LNKCTL_CCC, ccc); } /* Configure upstream component */ - pcie_capability_read_word(parent, PCI_EXP_LNKCTL, ®16); - parent_reg = reg16; - if (same_clock) - reg16 |= PCI_EXP_LNKCTL_CCC; - else - reg16 &= ~PCI_EXP_LNKCTL_CCC; - pcie_capability_write_word(parent, PCI_EXP_LNKCTL, reg16); + pcie_capability_clear_and_set_word(parent, PCI_EXP_LNKCTL, + PCI_EXP_LNKCTL_CCC, ccc); if (pcie_retrain_link(link)) { /* Training failed. Restore common clock configurations */ pci_err(parent, "ASPM: Could not configure common clock\n"); list_for_each_entry(child, &linkbus->devices, bus_list) - pcie_capability_write_word(child, PCI_EXP_LNKCTL, - child_reg[PCI_FUNC(child->devfn)]); - pcie_capability_write_word(parent, PCI_EXP_LNKCTL, parent_reg); + pcie_capability_clear_and_set_word(child, PCI_EXP_LNKCTL, + PCI_EXP_LNKCTL_CCC, + child_old_ccc[PCI_FUNC(child->devfn)]); + pcie_capability_clear_and_set_word(parent, PCI_EXP_LNKCTL, + PCI_EXP_LNKCTL_CCC, parent_old_ccc); } }