On Wed, Aug 02, 2023 at 02:44:52PM -0400, Frank Li wrote: > On Wed, Aug 02, 2023 at 11:31:38AM -0500, Bjorn Helgaas wrote: > > On Wed, Aug 02, 2023 at 11:57:47AM -0400, Frank Li wrote: > > > Introduce helper function dw_pcie_get_ltssm to retrieve SMLH_LTSS_STATE. > > > Add callback .pme_turn_off and .exit_from_l2 for platform specific PME > > > handling. > > > + * PCI Express Base Specification Rev 4.0 Section 5.3.3.2.1 PME > > > + * Synchronization Recommends 1ms to 10ms timeout to check L2 ready. > > > + */ > > > + ret = read_poll_timeout(dw_pcie_get_ltssm, val, val == DW_PCIE_LTSSM_L2_IDLE, > > > + 1000, 10000, false, pci); > > It would really be great to have a #define for this since the bare > > numbers are not very meaningful and they're not specific to DWC so a > > #define would let us find similar situations in other drivers. > > how about define as > > #define PCI_PME_TO_L2_TIMEOUT 10000 > > ret = read_poll_timeout(dw_pcie_get_ltssm, val, val == DW_PCIE_LTSSM_L2_IDLE, > PCI_PME_TO_L2_TIMEOUT/10, PCI_PME_TO_L2_TIMEOUT, false, pci); > > where is good place PCI_PME_TO_L2_TIMEOUT in? > > pcie-designware.h or pci.h? I think drivers/pci/pci.h since it's only useful inside drivers/pci, and it's not specific to dwc. Maybe "PCIE_" (not "PCI_") since this is a PCIe-specific thing. You could put it next to PCIE_LINK_RETRAIN_TIMEOUT_MS and add a "_US" suffix so we know what the units are. Bjorn
