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charset="utf-8" PCIe r6.0, section 7.9.15 requires PTM capability in exactly one function to control all PTM-capable functions. This makes PTM registers controller-level rather than per-function. Add a comment explaining why PTM capability registers are accessed using the standard DBI accessors instead of func_no indexed per-function accessors. Suggested-by: Niklas Cassel Signed-off-by: Aksh Garg Reviewed-by: Niklas Cassel Reviewed-by: Frank Li --- Changes from v4 to v5: - None Changes from v3 to v4: - Rebase Changes from v2 to v3: - Fixed the suggested nits v4: https://lore.kernel.org/all/20260129091753.490167-4-a-garg7@ti.com/ v3: https://lore.kernel.org/all/20260127085010.446116-4-a-garg7@ti.com/ v2: https://lore.kernel.org/all/20260122082538.309122-4-a-garg7@ti.com/ drivers/pci/controller/dwc/pcie-designware-ep.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/= controller/dwc/pcie-designware-ep.c index 6d3c35dd280f..dd48e60b513c 100644 --- a/drivers/pci/controller/dwc/pcie-designware-ep.c +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c @@ -1187,6 +1187,16 @@ int dw_pcie_ep_init_registers(struct dw_pcie_ep *ep) if (ep->ops->init) ep->ops->init(ep); =20 + /* + * PCIe r6.0, section 7.9.15 states that for endpoints that support PTM, + * this capability structure is required in exactly one function, which + * controls the PTM behavior of all PTM capable functions. This indicates + * the PTM capability structure represents controller-level registers + * rather than per-function registers. + * + * Therefore, PTM capability registers are configured using the standard = DBI + * accessors, instead of func_no indexed per-function accessors. + */ ptm_cap_base =3D dw_pcie_find_ext_capability(pci, PCI_EXT_CAP_ID_PTM); =20 /* --=20 2.34.1