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. s/dw_pcie_get_ltssm/dw_pcie_get_ltssm()/ > Add callback .pme_turn_off and .exit_from_l2 for platform specific PME > handling. > > Add common dw_pcie_suspend(resume)_noirq() API to avoid duplicated code > in dwc pci host controller platform driver. > > Typical L2 entry workflow/dw_pcie_suspend_noirq() > > 1. Transmit PME turn off signal to PCI devices and wait for PME_To_Ack. > 2. Await link entering L2_IDLE state. > > Typical L2 exit workflow/dw_pcie_resume_noirq() > > 1. Issue exit from L2 command. > 2. Reinitialize PCI host. > 3. Wait for link to become active. > > Signed-off-by: Frank Li <Frank.Li@xxxxxxx> > --- > Change from v6 to v7 > - change according to Manivannan's comments. > fix sleep value 100 (should be 1000 for 1ms). > + * 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); Thanks for the spec citation. Can you please reference the current spec, i.e., "PCIe r6.0, sec 5.3.3.2.1". s/Recommends/recommends/ 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. Bjorn
