diff options
| author | Jim Quinlan <james.quinlan@broadcom.com> | 2025-10-03 13:04:36 -0400 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2025-10-28 13:04:42 -0500 |
| commit | 9583f9d22991d2cfb5cc59a2552040c4ae98d998 (patch) | |
| tree | 5b67922b7521828dd79e2425bcbe69dc297f839d | |
| parent | 3a8660878839faadb4f1a6dd72c3179c1df56787 (diff) | |
PCI: brcmstb: Fix disabling L0s capability
caab002d5069 ("PCI: brcmstb: Disable L0s component of ASPM if requested")
set PCI_EXP_LNKCAP_ASPM_L1 and (optionally) PCI_EXP_LNKCAP_ASPM_L0S in
PCI_EXP_LNKCAP (aka PCIE_RC_CFG_PRIV1_LINK_CAPABILITY in brcmstb).
But instead of using PCI_EXP_LNKCAP_ASPM_L1 and PCI_EXP_LNKCAP_ASPM_L0S
directly, it used PCIE_LINK_STATE_L1 and PCIE_LINK_STATE_L0S, which are
Linux-created values that only coincidentally matched the PCIe spec.
b478e162f227 ("PCI/ASPM: Consolidate link state defines") later changed
them so they no longer matched the PCIe spec, so the bits ended up in the
wrong place in PCI_EXP_LNKCAP.
Use PCI_EXP_LNKCAP_ASPM_L0S to clear L0s support when there's an
'aspm-no-l0s' property. Rely on brcmstb hardware to advertise L0s and/or
L1 support otherwise.
Fixes: caab002d5069 ("PCI: brcmstb: Disable L0s component of ASPM if requested")
Reported-by: Bjorn Helgaas <bhelgaas@google.com>
Closes: https://lore.kernel.org/linux-pci/20250925194424.GA2197200@bhelgaas
Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
[mani: reworded subject and description, added closes tag and CCed stable]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20251003170436.1446030-1-james.quinlan@broadcom.com
| -rw-r--r-- | drivers/pci/controller/pcie-brcmstb.c | 10 |
1 files changed, 3 insertions, 7 deletions
diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c index 9afbd02ded35..7e9b2f6a604a 100644 --- a/drivers/pci/controller/pcie-brcmstb.c +++ b/drivers/pci/controller/pcie-brcmstb.c @@ -48,7 +48,6 @@ #define PCIE_RC_CFG_PRIV1_LINK_CAPABILITY 0x04dc #define PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_MAX_LINK_WIDTH_MASK 0x1f0 -#define PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_ASPM_SUPPORT_MASK 0xc00 #define PCIE_RC_CFG_PRIV1_ROOT_CAP 0x4f8 #define PCIE_RC_CFG_PRIV1_ROOT_CAP_L1SS_MODE_MASK 0xf8 @@ -1075,7 +1074,7 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie) void __iomem *base = pcie->base; struct pci_host_bridge *bridge; struct resource_entry *entry; - u32 tmp, burst, aspm_support, num_lanes, num_lanes_cap; + u32 tmp, burst, num_lanes, num_lanes_cap; u8 num_out_wins = 0; int num_inbound_wins = 0; int memc, ret; @@ -1175,12 +1174,9 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie) /* Don't advertise L0s capability if 'aspm-no-l0s' */ - aspm_support = PCIE_LINK_STATE_L1; - if (!of_property_read_bool(pcie->np, "aspm-no-l0s")) - aspm_support |= PCIE_LINK_STATE_L0S; tmp = readl(base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); - u32p_replace_bits(&tmp, aspm_support, - PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_ASPM_SUPPORT_MASK); + if (of_property_read_bool(pcie->np, "aspm-no-l0s")) + tmp &= ~PCI_EXP_LNKCAP_ASPM_L0S; writel(tmp, base + PCIE_RC_CFG_PRIV1_LINK_CAPABILITY); /* 'tmp' still holds the contents of PRIV1_LINK_CAPABILITY */ |