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    Subject[PATCH v4 4/6] 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 | 58 +++++++++++++++++++++++----
    1 file changed, 51 insertions(+), 7 deletions(-)

    diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
    index 1b0de0c7da60..4c79aff66de7 100644
    --- a/drivers/pci/controller/pcie-brcmstb.c
    +++ b/drivers/pci/controller/pcie-brcmstb.c
    @@ -193,6 +193,7 @@ 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[] = {
    "vpcie12v-supply",
    @@ -304,22 +305,65 @@ struct brcm_pcie {
    void (*bridge_sw_init_set)(struct brcm_pcie *pcie, u32 val);
    struct regulator_bulk_data supplies[PCIE_BRCM_MAX_EP_REGULATORS];
    unsigned int num_supplies;
    + bool ep_wakeup_capable;
    };

    -static int brcm_set_regulators(struct brcm_pcie *pcie, bool on)
    +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;
    +}
    +
    +enum {
    + TURN_OFF, /* Turn regulators off, unless an EP is wakeup-capable */
    + TURN_OFF_ALWAYS, /* Turn regulators off, no exceptions */
    + TURN_ON, /* Turn regulators on, unless pcie->ep_wakeup_capable */
    +};
    +
    +static int brcm_set_regulators(struct brcm_pcie *pcie, int how)
    +{
    + struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
    struct device *dev = pcie->dev;
    int ret;

    if (!pcie->num_supplies)
    return 0;
    - if (on)
    + if (how == TURN_ON) {
    + 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;
    + }
    + } else if (how == TURN_OFF) {
    + /*
    + * If at least one device on this bus is enabled as a
    + * wake-up source, do not turn off regulators.
    + */
    + pcie->ep_wakeup_capable = false;
    + if (bridge->bus && brcm_pcie_link_up(pcie)) {
    + pci_walk_bus(bridge->bus, pci_dev_may_wakeup, &pcie->ep_wakeup_capable);
    + if (pcie->ep_wakeup_capable)
    + return 0;
    + }
    + }
    +
    + if (how == TURN_ON)
    ret = regulator_bulk_enable(pcie->num_supplies, pcie->supplies);
    else
    ret = regulator_bulk_disable(pcie->num_supplies, pcie->supplies);
    if (ret)
    dev_err(dev, "failed to %s EP regulators\n",
    - on ? "enable" : "disable");
    + how == TURN_ON ? "enable" : "disable");
    return ret;
    }

    @@ -1206,7 +1250,7 @@ static int brcm_pcie_suspend(struct device *dev)
    brcm_phy_stop(pcie);
    clk_disable_unprepare(pcie->clk);

    - return brcm_set_regulators(pcie, false);
    + return brcm_set_regulators(pcie, TURN_OFF);
    }

    static int brcm_pcie_resume(struct device *dev)
    @@ -1221,7 +1265,7 @@ static int brcm_pcie_resume(struct device *dev)
    if (ret)
    return ret;

    - ret = brcm_set_regulators(pcie, true);
    + ret = brcm_set_regulators(pcie, TURN_ON);
    if (ret)
    return ret;

    @@ -1261,7 +1305,7 @@ static void __brcm_pcie_remove(struct brcm_pcie *pcie)
    brcm_phy_stop(pcie);
    reset_control_assert(pcie->rescal);
    clk_disable_unprepare(pcie->clk);
    - brcm_set_regulators(pcie, false);
    + brcm_set_regulators(pcie, TURN_OFF_ALWAYS);
    }

    static int brcm_pcie_remove(struct platform_device *pdev)
    @@ -1360,7 +1404,7 @@ static int brcm_pcie_probe(struct platform_device *pdev)
    goto fail;
    }

    - ret = brcm_set_regulators(pcie, true);
    + ret = brcm_set_regulators(pcie, TURN_ON);
    if (ret)
    goto fail;

    --
    2.17.1
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