Hi Bjorn, On 2017/8/29 2:33, Bjorn Helgaas wrote: > On Mon, Aug 28, 2017 at 10:22:24AM +0800, Shawn Lin wrote: >> Hi Bjorn, >> >> On 2017/8/26 5:38, Bjorn Helgaas wrote: >>> On Wed, Aug 23, 2017 at 03:01:13PM +0800, Shawn Lin wrote: >>>> >> >> ... >> >>> >>> I applied these to pci/host-rockchip except for these: >>> >>> PCI: rockchip: fix system hang up if activating CONFIG_DEBUG_SHIRQ >>> PCI: rockchip: fix missing phy manipulation for legacy phy >>> >>> I'm not really happy with the devm/clk_prepare_enable situation, so >>> I'm waiting to see if a better solution emerges. >>> >>> I went ahead and applied the tweaks I proposed to the earlier "PCI: >>> rockchip: Add per-lane PHY support" and "PCI: rockchip: Idle inactive >>> PHY(s)" patches. I *think* those make the "fix missing phy >>> manipulation for legacy phy" patch unnecessary. >>> >>> But please take a look and make sure. If I went the wrong direction, >>> I'll gladly back it out. >> >> I tested both of legacy and per-lane PHY mode, and it works fine. >> >> But just a nit: >> >> with legacy PHY, we could avoid to print the following message >> which is confusing as for legacy PHY mode, we couldn't idle >> any inactive lanes. >> >> [ 0.655192] rockchip-pcie f8000000.pcie: idling lane 1 >> [ 0.655696] rockchip-pcie f8000000.pcie: idling lane 2 >> [ 0.656194] rockchip-pcie f8000000.pcie: idling lane 3 >> >> So I think we could return 0xf for legacy PHY mode like this: >> >> static u8 rockchip_pcie_lane_map(struct rockchip_pcie *rockchip) >> u8 map; >> >> if (rockchip->legacy_phy) >> - return BIT(0); >> + return GENMASK(MAX_LANE_NUM - 1, 0); > > When we're using legacy PHY mode, this changes lanes_map from 0x1 to > 0xf. That means we won't print the "idling lane 1" message. It > *also* means we won't call phy_power_off() for lanes 1-3. Is that the > correct behavior? Does the legacy PHY mode actually use all 4 PHYs? Yes, it's the correct behaviour. The 4 PHYs is abstraction of 4 lanes for per-lane PHY mode, but for legacy PHY mode, PHY represents a single component managing 4 lanes together. So no matter how many lanes are used, we couldn't call phy_power_off for legacy PHY mode until we really want to power off the PHY. That is why we need to recontruct the pcie and phy driver to migrate to per-lane PHY mode as we could treat each lane as a phy object and let phy driver do idling work in the phy_power_off callback instead of power-off work if ref count isn't decreased to zero. Also I think the key point here is that for legacy PHY mode, only phys[0] is vaild, so there is no difference if we call phy_power_off for phys[1..3] as you did, because PHY API will check the phy object and won't do anything if seeing invalid/NULL phy object. So changing lanes_map from 0x1 to 0xf is only silent the "idling lane x" log. > > >
