diff options
Diffstat (limited to 'drivers/pci/pcie/aspm.c')
| -rw-r--r-- | drivers/pci/pcie/aspm.c | 25 |
1 files changed, 14 insertions, 11 deletions
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 0725511cbeb5..82ce34e2ef53 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -381,7 +381,6 @@ static void encode_l12_threshold(u32 threshold_us, u32 *scale, u32 *value) } struct aspm_register_info { - u32 support:2; u32 enabled:2; u32 latency_encoding_l0s; u32 latency_encoding_l1; @@ -400,7 +399,6 @@ static void pcie_get_aspm_reg(struct pci_dev *pdev, u32 reg32; pcie_capability_read_dword(pdev, PCI_EXP_LNKCAP, ®32); - info->support = (reg32 & PCI_EXP_LNKCAP_ASPMS) >> 10; info->latency_encoding_l0s = (reg32 & PCI_EXP_LNKCAP_L0SEL) >> 12; info->latency_encoding_l1 = (reg32 & PCI_EXP_LNKCAP_L1EL) >> 15; pcie_capability_read_word(pdev, PCI_EXP_LNKCTL, ®16); @@ -550,6 +548,7 @@ static void aspm_calc_l1ss_info(struct pcie_link_state *link, static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist) { struct pci_dev *child = link->downstream, *parent = link->pdev; + u32 parent_lnkcap, child_lnkcap; struct pci_bus *linkbus = parent->subordinate; struct aspm_register_info upreg, dwreg; @@ -560,24 +559,26 @@ static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist) return; } - /* Get upstream/downstream components' register state */ - pcie_get_aspm_reg(parent, &upreg); - pcie_get_aspm_reg(child, &dwreg); - /* * If ASPM not supported, don't mess with the clocks and link, * bail out now. */ - if (!(upreg.support & dwreg.support)) + pcie_capability_read_dword(parent, PCI_EXP_LNKCAP, &parent_lnkcap); + pcie_capability_read_dword(child, PCI_EXP_LNKCAP, &child_lnkcap); + if (!(parent_lnkcap & child_lnkcap & PCI_EXP_LNKCAP_ASPMS)) return; /* Configure common clock before checking latencies */ pcie_aspm_configure_common_clock(link); /* - * Re-read upstream/downstream components' register state - * after clock configuration + * Re-read upstream/downstream components' register state after + * clock configuration. L0s & L1 exit latencies in the otherwise + * read-only Link Capabilities may change depending on common clock + * configuration (PCIe r5.0, sec 7.5.3.6). */ + pcie_capability_read_dword(parent, PCI_EXP_LNKCAP, &parent_lnkcap); + pcie_capability_read_dword(child, PCI_EXP_LNKCAP, &child_lnkcap); pcie_get_aspm_reg(parent, &upreg); pcie_get_aspm_reg(child, &dwreg); @@ -588,8 +589,9 @@ static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist) * given link unless components on both sides of the link each * support L0s. */ - if (dwreg.support & upreg.support & PCIE_LINK_STATE_L0S) + if (parent_lnkcap & child_lnkcap & PCI_EXP_LNKCAP_ASPM_L0S) link->aspm_support |= ASPM_STATE_L0S; + if (dwreg.enabled & PCIE_LINK_STATE_L0S) link->aspm_enabled |= ASPM_STATE_L0S_UP; if (upreg.enabled & PCIE_LINK_STATE_L0S) @@ -598,8 +600,9 @@ static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist) link->latency_dw.l0s = calc_l0s_latency(dwreg.latency_encoding_l0s); /* Setup L1 state */ - if (upreg.support & dwreg.support & PCIE_LINK_STATE_L1) + if (parent_lnkcap & child_lnkcap & PCI_EXP_LNKCAP_ASPM_L1) link->aspm_support |= ASPM_STATE_L1; + if (upreg.enabled & dwreg.enabled & PCIE_LINK_STATE_L1) link->aspm_enabled |= ASPM_STATE_L1; link->latency_up.l1 = calc_l1_latency(upreg.latency_encoding_l1); |