Replace the three dw_pcie_find_capability(pci, PCI_CAP_ID_EXP) calls in the qcom-ep driver with dw_pcie_get_pcie_cap().
qcom_pcie_perst_deassert() is the point where the controller resources have just been enabled and DBI becomes accessible, so the offset is looked up and cached there. Both the L0s and the L1 exit latency are then programmed using that same cached offset instead of walking the capability list again. qcom_pcie_ep_icc_update() may run from the global IRQ handler, which is requested before the PERST# IRQ. The helper performs its lookup at that point of use, i.e. exactly where the open coded search happened before, so this change neither adds nor moves a DBI access and does not introduce a new race with the PERST# handler. Signed-off-by: Hans Zhang <[email protected]> --- drivers/pci/controller/dwc/pcie-qcom-ep.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/pci/controller/dwc/pcie-qcom-ep.c b/drivers/pci/controller/dwc/pcie-qcom-ep.c index 56184e6ca6e6..413a1582f300 100644 --- a/drivers/pci/controller/dwc/pcie-qcom-ep.c +++ b/drivers/pci/controller/dwc/pcie-qcom-ep.c @@ -307,14 +307,15 @@ static void qcom_pcie_dw_write_dbi2(struct dw_pcie *pci, void __iomem *base, static void qcom_pcie_ep_icc_update(struct qcom_pcie_ep *pcie_ep) { struct dw_pcie *pci = &pcie_ep->pci; - u32 offset, status; + u8 offset; + u32 status; int speed, width; int ret; if (!pcie_ep->icc_mem) return; - offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); + offset = dw_pcie_get_pcie_cap(pci); status = readw(pci->dbi_base + offset + PCI_EXP_LNKSTA); speed = FIELD_GET(PCI_EXP_LNKSTA_CLS, status); @@ -397,7 +398,8 @@ static int qcom_pcie_perst_deassert(struct dw_pcie *pci) { struct qcom_pcie_ep *pcie_ep = to_pcie_ep(pci); struct device *dev = pci->dev; - u32 val, offset; + u32 val; + u8 offset; int ret; ret = pm_runtime_resume_and_get(dev); @@ -492,13 +494,12 @@ static int qcom_pcie_perst_deassert(struct dw_pcie *pci) dw_pcie_dbi_ro_wr_en(pci); /* Set the L0s Exit Latency to 2us-4us = 0x6 */ - offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); + offset = dw_pcie_get_pcie_cap(pci); val = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP); FIELD_MODIFY(PCI_EXP_LNKCAP_L0SEL, &val, 0x6); dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, val); /* Set the L1 Exit Latency to be 32us-64 us = 0x6 */ - offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); val = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP); FIELD_MODIFY(PCI_EXP_LNKCAP_L1EL, &val, 0x6); dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, val); -- 2.43.0
