From: Jim Quinlan james.quinlan@broadcom.com
[ Upstream commit 9583f9d22991d2cfb5cc59a2552040c4ae98d998 ]
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 [ adapted context due to missing link width negotiation defines and variables ] Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/pci/controller/pcie-brcmstb.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c index 9bcf4c68058e..8850a15b0aec 100644 --- a/drivers/pci/controller/pcie-brcmstb.c +++ b/drivers/pci/controller/pcie-brcmstb.c @@ -46,7 +46,6 @@ #define PCIE_RC_CFG_PRIV1_ID_VAL3_CLASS_CODE_MASK 0xffffff
#define PCIE_RC_CFG_PRIV1_LINK_CAPABILITY 0x04dc -#define PCIE_RC_CFG_PRIV1_LINK_CAPABILITY_ASPM_SUPPORT_MASK 0xc00
#define PCIE_RC_DL_MDIO_ADDR 0x1100 #define PCIE_RC_DL_MDIO_WR_DATA 0x1104 @@ -867,7 +866,7 @@ 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; + u32 tmp, burst; int num_out_wins = 0; int ret, memc;
@@ -971,12 +970,9 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie) writel(tmp, base + PCIE_MISC_RC_BAR3_CONFIG_LO);
/* 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);
/*