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    Subject[PATCH v6 8/9] PCI: brcmstb: Do not turn off regulators if EP can wake up
    Date
    If any downstream device may wake up during S2/S3 suspend, we do not want
    to turn off its power when suspending.

    Signed-off-by: Jim Quinlan <jim2101024@gmail.com>
    ---
    drivers/pci/controller/pcie-brcmstb.c | 49 ++++++++++++++++++++++++---
    1 file changed, 45 insertions(+), 4 deletions(-)

    diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
    index 6635e143cfcb..18b9f7c97864 100644
    --- a/drivers/pci/controller/pcie-brcmstb.c
    +++ b/drivers/pci/controller/pcie-brcmstb.c
    @@ -192,6 +192,7 @@ static inline void brcm_pcie_bridge_sw_init_set_generic(struct brcm_pcie *pcie,
    static inline void brcm_pcie_perst_set_4908(struct brcm_pcie *pcie, u32 val);
    static inline void brcm_pcie_perst_set_7278(struct brcm_pcie *pcie, u32 val);
    static inline void brcm_pcie_perst_set_generic(struct brcm_pcie *pcie, u32 val);
    +static bool brcm_pcie_link_up(struct brcm_pcie *pcie);

    static const char * const supplies[] = {
    "vpcie3v3",
    @@ -304,8 +305,20 @@ struct brcm_pcie {
    void (*bridge_sw_init_set)(struct brcm_pcie *pcie, u32 val);
    struct regulator_bulk_data supplies[ARRAY_SIZE(supplies)];
    unsigned int num_supplies;
    + bool ep_wakeup_capable;
    };

    +static int pci_dev_may_wakeup(struct pci_dev *dev, void *data)
    +{
    + bool *ret = data;
    +
    + if (device_may_wakeup(&dev->dev)) {
    + *ret = true;
    + dev_dbg(&dev->dev, "disable cancelled for wake-up device\n");
    + }
    + return (int) *ret;
    +}
    +
    static int brcm_regulators_on(struct brcm_pcie *pcie)
    {
    struct device *dev = pcie->dev;
    @@ -313,6 +326,18 @@ static int brcm_regulators_on(struct brcm_pcie *pcie)

    if (!pcie->num_supplies)
    return 0;
    +
    + if (pcie->ep_wakeup_capable) {
    + /*
    + * We are resuming from a suspend. In the previous suspend
    + * we did not disable the power supplies, so there is no
    + * need to enable them (and falsely increase their usage
    + * count).
    + */
    + pcie->ep_wakeup_capable = false;
    + return 0;
    + }
    +
    ret = regulator_bulk_enable(pcie->num_supplies, pcie->supplies);
    if (ret)
    dev_err(dev, "failed to enable EP regulators\n");
    @@ -320,13 +345,28 @@ static int brcm_regulators_on(struct brcm_pcie *pcie)
    return ret;
    }

    -static int brcm_regulators_off(struct brcm_pcie *pcie)
    +static int brcm_regulators_off(struct brcm_pcie *pcie, bool force)
    {
    + struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
    struct device *dev = pcie->dev;
    int ret;

    if (!pcie->num_supplies)
    return 0;
    +
    + pcie->ep_wakeup_capable = false;
    +
    + if (!force && bridge->bus && brcm_pcie_link_up(pcie)) {
    + /*
    + * If at least one device on this bus is enabled as a
    + * wake-up source, do not turn off regulators.
    + */
    + pci_walk_bus(bridge->bus, pci_dev_may_wakeup,
    + &pcie->ep_wakeup_capable);
    + if (pcie->ep_wakeup_capable)
    + return 0;
    + }
    +
    ret = regulator_bulk_disable(pcie->num_supplies, pcie->supplies);
    if (ret)
    dev_err(dev, "failed to disable EP regulators\n");
    @@ -1248,7 +1288,7 @@ static int brcm_pcie_suspend(struct device *dev)
    reset_control_rearm(pcie->rescal);
    clk_disable_unprepare(pcie->clk);

    - return brcm_regulators_off(pcie);
    + return brcm_regulators_off(pcie, false);
    }

    static int brcm_pcie_resume(struct device *dev)
    @@ -1264,6 +1304,7 @@ static int brcm_pcie_resume(struct device *dev)
    ret = reset_control_reset(pcie->rescal);
    if (ret)
    goto err_disable_clk;
    +
    ret = brcm_regulators_on(pcie);
    if (ret)
    goto err_reset;
    @@ -1311,7 +1352,7 @@ static void __brcm_pcie_remove(struct brcm_pcie *pcie)
    reset_control_rearm(pcie->rescal);
    clk_disable_unprepare(pcie->clk);
    if (pcie->num_supplies) {
    - brcm_regulators_off(pcie);
    + brcm_regulators_off(pcie, true);
    regulator_bulk_free(pcie->num_supplies, pcie->supplies);
    }
    }
    @@ -1382,7 +1423,7 @@ static int brcm_pcie_pci_subdev_prepare(struct pci_bus *bus, int devfn,
    return 0;

    err_out1:
    - brcm_regulators_off(pcie);
    + brcm_regulators_off(pcie, true);
    err_out0:
    regulator_bulk_free(pcie->num_supplies, pcie->supplies);
    pcie->num_supplies = 0;
    --
    2.17.1
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