diff options
| author | Bjorn Helgaas <bhelgaas@google.com> | 2025-11-10 16:22:25 -0600 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2025-11-12 18:47:16 -0600 |
| commit | 4495bffd86ba0fdabfaef0c41d12f68ec2a1e05b (patch) | |
| tree | 3784f246ab60cabd1a5a690cab2233f49116c5ad /drivers | |
| parent | 3a8660878839faadb4f1a6dd72c3179c1df56787 (diff) | |
| download | net-4495bffd86ba0fdabfaef0c41d12f68ec2a1e05b.tar.gz | |
PCI/ASPM: Cache L0s/L1 Supported so advertised link states can be overridden
Defective devices sometimes advertise support for ASPM L0s or L1 states
even if they don't work correctly.
Cache the L0s Supported and L1 Supported bits early in enumeration so
HEADER quirks can override the ASPM states advertised in Link Capabilities
before pcie_aspm_cap_init() enables ASPM.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Shawn Lin <shawn.lin@rock-chips.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Link: https://patch.msgid.link/20251110222929.2140564-2-helgaas@kernel.org
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/pci/pcie/aspm.c | 12 | ||||
| -rw-r--r-- | drivers/pci/probe.c | 7 |
2 files changed, 11 insertions, 8 deletions
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c index 7cc8281e70119b..15d50c08907037 100644 --- a/drivers/pci/pcie/aspm.c +++ b/drivers/pci/pcie/aspm.c @@ -830,7 +830,6 @@ static void pcie_aspm_override_default_link_state(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; u16 parent_lnkctl, child_lnkctl; struct pci_bus *linkbus = parent->subordinate; @@ -845,9 +844,8 @@ static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist) * If ASPM not supported, don't mess with the clocks and link, * bail out now. */ - 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)) + if (!(parent->aspm_l0s_support && child->aspm_l0s_support) && + !(parent->aspm_l1_support && child->aspm_l1_support)) return; /* Configure common clock before checking latencies */ @@ -859,8 +857,6 @@ static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist) * 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_capability_read_word(parent, PCI_EXP_LNKCTL, &parent_lnkctl); pcie_capability_read_word(child, PCI_EXP_LNKCTL, &child_lnkctl); @@ -880,7 +876,7 @@ 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 (parent_lnkcap & child_lnkcap & PCI_EXP_LNKCAP_ASPM_L0S) + if (parent->aspm_l0s_support && child->aspm_l0s_support) link->aspm_support |= PCIE_LINK_STATE_L0S; if (child_lnkctl & PCI_EXP_LNKCTL_ASPM_L0S) @@ -889,7 +885,7 @@ static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist) link->aspm_enabled |= PCIE_LINK_STATE_L0S_DW; /* Setup L1 state */ - if (parent_lnkcap & child_lnkcap & PCI_EXP_LNKCAP_ASPM_L1) + if (parent->aspm_l1_support && child->aspm_l1_support) link->aspm_support |= PCIE_LINK_STATE_L1; if (parent_lnkctl & child_lnkctl & PCI_EXP_LNKCTL_ASPM_L1) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index c83e75a0ec1263..de72ceaea28562 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1663,6 +1663,13 @@ void set_pcie_port_type(struct pci_dev *pdev) if (reg32 & PCI_EXP_LNKCAP_DLLLARC) pdev->link_active_reporting = 1; +#ifdef CONFIG_PCIEASPM + if (reg32 & PCI_EXP_LNKCAP_ASPM_L0S) + pdev->aspm_l0s_support = 1; + if (reg32 & PCI_EXP_LNKCAP_ASPM_L1) + pdev->aspm_l1_support = 1; +#endif + parent = pci_upstream_bridge(pdev); if (!parent) return; |